Hey, we were all teenagers once. That doesn’t mean we have to dress like it for the rest of our lives. Everything else matures and develops—why not fashion sense?

Head out for a night on the town and you’ll start to see them: Men who look like boys, all because of the outfits they picked. (Presumably they chose their own outfits; sometimes it looks like they might have gotten some help from mom.) Once you spot one, you’ll see them all, like when you notice an ant on your shoe and suddenly realize you’ve been standing over a hidden swarm. Their numbers are legion.

Too many men are frozen in their teenage years when it comes to their sense of style, so we decided to pull together a list of the worst fashion missteps that create this distressingly prevalent man-boy look.

Nothing says ‘I’m trying too hard’ more than these styles.

But we’re not cruel; we’re not just here to berate our friends for their fashion ignorance. We’re here to help.

So along with each fashion faux pas, we’ve got some expert advice for how guys can go from juvenile to proven style. Start by skipping:

1. Shiny, Shiny, Shiny Polyester

Remember when every dude’s party outfit featured a shiny polyester button-down with a Dragonball Z print, or, like, a skull, or just a few rockabilly flames? Yeah, that was the 2000s. Leave those club shirts where they belong, which is in a dark, shameful corner of your high school days.

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It’s not just the cartoon prints that scream immaturity in these shirts. It’s the material, a polyester so shiny it looks like the shirt is covered in a thin film of oil. And that brings us to our first remedy for self-infantilizing fashion mistakes: Understand fabrics, and recognize quality.

You don’t need every piece of clothing you own to be cashmere, but if you’re serious about dressing like an adult, you do need to pay a little more for your wardrobe. Higher-quality materials will last longer and look better. Just ask Annie Heyward, a personal stylist who works out of St. Louis and Nashville.

“A polyester suit might be more affordable, but the hand [feel] of the fabric will be rough and inexpensive,” she says. “More importantly, synthetic fabrics won’t last as long or read as sophisticated.”

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That’s not to say all synthetic blends are off limits. If you’re looking for a T-shirt, a bit of spandex in the mix might not hurt.

As Angela Moore, another St. Louis-based personal stylist, explains, “Spandex and high-end cotton blends can be even better, giving you a nice fit with a bit of stretch.” So unlike those shiny shirts, there’s pretty much zero chance of an awkward split or tear on a date.

FashionBeans’ Picks

The Basic:  The Nautica Men’s Solid Crew Neck Short Sleeve Pocket T-Shirt is the basic you need in your life. Available in a rainbow spectrum of shades (but always plain, please), we’re digging the Mustard Field or Monaco Blue if you want a pop of color. The cheeky little pocket detail won’t carry your smartphone but it might just hold one credit card.

Nautica Men’s Solid Crew Neck Short Sleeve Pocket T-Shirt, from $15.99 on Amazon

The Trendsetter:  Trust us when we say you can’t go wrong with a plain black tee. The A|X Armani Exchange Men’s Cotton Spandex Short Sleeve Jersey T-shirt one comes in all the neutrals – black, navy, gray or white – so try one, and then buy all four to up your everyday staples game.

A|X Armani Exchange Men’s Cotton Spandex Short Sleeve Jersey T-shirt, $40 on Amazon

The Luxe: With just a hint of spandex, this v-neck tee will become the most versatile piece in your closet (disclaimer: probably). Finding the right white tee is like the holy grail of style – and this Paige number comes pretty close in shape and fit. Wear it with jeans or casual pants and layer up with a loose cardigan or jumper when temperatures drop. It will go with a-n-y-t-h-i-n-g.

PAIGE Men’s Grayson Tech Jersey V Neck T-Shirt, $65.00 on Amazon

2. Jordans Off the Court

Even the most ardent sneakerhead in the world has to admit it: Elaborate basketball shoes just don’t go with business attire.

That doesn’t stop guys from trying to show off their latest high-dollar kicks even when they have no intention of picking up a quick game in between sales calls.

Maja Hitij/Getty

Nothing reveals high school-era arrested development more than excessive pride over your sneakers. It’s cool to collect Air Jordans. It’s awesome to have a closet full of kicks. We don’t dispute that. We are down with the sneakerheads. But you need to know when your new shoes make the right statement and when they just say, “Look what I got for my birthday!”

So in addition to the latest Nike collab, be sure to save some cash for a decent pair of dress shoes.

“Shoes set the tone for your outfit, so investing in a good pair of dress shoes is essential,” says Moore. “The Oxford dress shoes are the best, hands down. They are incredibly versatile and will go with 99 percent of the items in your wardrobe.”

It might be tempting to take your adult-shoe money and throw down on a pair of LeBron 15 Ghosts instead. Resist the urge.

“Think of the return on your investment,” Heyward says. “A classic pair of black cap-toed Oxfords and a brown pair of suede or leather driving loafers can be styled [in myriad] ways, and although only just a few of the ‘essential’ shoes every man should own, these are a great starting point when building your shoe wardrobe.”

Admittedly, they may not be quite as comfy as a pair of basketball sneakers but if you’re making the man-child transition to boy-man, a pair of Oxford dress shoes will stand you in good stead – literally. Don’t be tempted to go back to your Jordans’ roots with lurid colors. Stick to neutrals and you’ll get more mileage out of your new kicks.

FashionBeans’ Picks

The Basic: If the whole dress shoe thing is a step too far there are more casual options that fall somewhere between sneaker and boardroom gear. In multi-textured navy, with a contrast sole, Steve Madden Rayder Oxford’s are like Oxfords off-duty, meaning you can wear them for both weekday and weekends i.e. double the cost-per-wear potential.

Steve Madden Men’s Rayder Oxford, from $40.50 at Amazon

The Trendsetter: Calvin Klein is known for its clean aesthetic so think of their Brodie Oxford as the no-bullshit approach to dress shoes. No fussy details here, just a slick, black leather shoe that your mom would be proud of. Just don’t forget your shoe polish…

Calvin Klein Men’s Brodie Oxford, from $71.37 at Amazon

The Luxe: In ‘coffee suede’ brown color (yep even the color palette sounds grown-up), these ECCO Men’s Wingtip Oxfords have all the classic brogue punching you’d expect, but the soft nubuck suede makes them feel less stiff and formal than other dress shoes – aka a good stepping stone if you’re finding it tough to move on from your Nike high-tops.

ECCO Men’s Kenton Brogue Tie Oxford, from $199.95 on Amazon

Being an adult means making sacrifices, so buy the boring shoes already.

3. Supersized Shirts

Thrifting has become cool again, even for people with the financial means to shop elsewhere. If you’re into the thrifting game for environmental reasons or just to save a few bucks on fashion from decades past, remember as you dig through the racks that there’s no excuse for baggy, oversized button-downs as an adult.

Too many adult men never took the time to understand how clothes actually fit, and that can lead to a guy swimming in a baggy shirt like a kid dressing up in daddy’s suit.

So how do you know if a dress shirt fits you properly?

If you have to ask, the shirt is too big.

“The shoulder seam of any garment should sit just outside the outside edge of your shoulder,” says Moore. “If it extends down your arm, try going down a size. A droopy shoulder never looks polished.”

As for the collar, there’s a simple test to determine whether you’re going too large or too small.

“When it comes to a good dress-shirt or button-up, the collar shouldn’t feel constricting,” says Heyward. “You should be able to fit one finger inside your buttoned collar without it choking you! Two is too much.”

Of course, the major factor in proper fitting is how the shirt lays across your chest. There are also a few easy ways to test that all-important dimension, Heyward explains.

“The body of the shirt should fit closely around your torso—no more than 2-3 inches of fabric on either side of the waist,” she says. “If the buttons are pulling across your chest or torso, it’s too small. One easy way to tell is if the shirt is tight across your shoulder blades or not. If it is, it’s too small.”

So how do you know if the shirt is too big? If you have to ask, the shirt is too big.

Oh, and the same goes for T-shirts, if you’re rocking a more casual look. You need that T-shirt to fit you properly.

“The sleeves of a short sleeved tee or polo should hit around mid-bicep and lightly hug your arm,” says Moore. “You don’t want there to be a bunch of room around the bicep since that looks cheap, tacky, and makes your arms look really small.”

So, you’re into baggy shirts but fitted dress shirts are off limits? Luckily there’s a compromise: loose-fit print shirts are enjoying a major moment. Justin Bieber we’re looking at you… These are the kind of button-downs you wear for poker nights with the boys, or eggs and avo brunches with your gf. Keep the jazzy shirt for your casual wardrobe only. And remember the key styling principal here: relaxed-fit, but never so-baggy-you-get-lost-in-it.

FashionBeans’ Picks

The Basic: Hawaiian shirts are having a revival, and you don’t have to be on holiday to wear one. Meet the way to work a toned-down version. The muted print and grey colorway of Youstar’s Casual Hawaiian Tropical Print button down makes it more wearable than the loud versions you’ll get out once in a blue moon for vacation.

Youstar Casual Hawaiian Tropical Print Button Down Shirt, $14.97 on Amazon

The Trendsetter: King Kong has got nothing on WHAT ON EARTH’s fun button-down *zooms in*. Go ape in this irreverent gorilla print relaxed fit shirt. Though the print’s pretty wild, the dark black colorway reigns it in a bit.

WHAT ON EARTH Men’s Bigfoot Print Camp Shirt, from $34.94 on Amazon

The Luxe: Okay if you want to do LOUD, say ‘aloha’ to HAWES & CURTIS’ vacation-inspired print number. You’ll be the walking equivalent of a beach postcard. The print may be garish but the relaxed fit keeps it looking fresh.

HAWES & CURTIS Mens Blue and Yellow Hawaiian Print Relaxed Shirt, $65.50 at Amazon

4. Silly Jeans [That] are Not [Your] Lover

Okay, let’s talk jeans. We’re not going to sit here and tell you they aren’t “appropriate” for the workplace. Maybe you work in media *cough*.

And we’re not going to pretend that “getting” to wear jeans on Casual Friday is some sort of tremendous favor your employer does for you.

Jeans are just denim pants, and in the right circumstances, they can even be somewhat dressy. Somewhat.

But not all jeans are created equal.

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“Light-wash tapered jeans are the worst. Nobody looks good in those,” says Moore. “Polished, dark-wash denim free of distressing, rips, or tears will always look expensive and professional.”

Even worse than the tapered legs, Heyward says, are jeans that simply have too much going on. Your pants don’t need slogans or designs or healing crystals sewn into the crotch to be fashionable. Quite the opposite, in fact.

“In general, steer clear from anything too trendy—overly distressed styles, excessive whispering, and, my ultimate ‘no-no,’ the bedazzled, grommeted, or heavily cross-stitched seat with excessive logos,” says Heyward. “Nothing says ‘I’m trying too hard’ more than these styles.”

Bob Chamberlain/TPN

Trying too hard is a clear indication of amateurism, and what are children if not amateur adults? That’s why jeans that do too much make you look like a child. Keep it simple from the waist down. Get on board with jeans you could just about wear to the office and nobody would bat an eyelid.

As Moore suggests, dark-wash, straight-cut jeans are where it’s at for manly denim. Just because they’re not silly, doesn’t mean they have to be ‘sensible’ dad jeans…

FashionBeans’ Picks

The Basic: For basics with durability, you can’t go wrong with this pair of dark wash Lee jeans. With a straight leg and plain back pocket styling, there are no bells and whistles but, get the fit right, and they’ll work with tees and shirts alike.  

LEE Men’s Relaxed Fit Straight Leg Jean, $17.25 from Amazon

The Trendsetter: Levi jeans are every style maven’s denim staples for a reason. These 511’s are slim-fit and uber-dark, making them pretty damn flattering on. Go grown-up by wearing them with dress shoes, or do weekend mode in a pair of Converse.

Levi’s Men’s 511 Slim Fit Jean, from $39.99 at Amazon

The Luxe: More slim-fits that straddle the line between casual jeans and smart trousers, thanks to that dark wash and subtle contrast stitching. Plus, all that low-key detail in these PAIGE slim fits means you can go louder with your top (see our print shirts, above).

PAIGE Men’s Federal Slim-Fit Jean In Cellar, from $105.53 at Amazon

5. OveremPHASis on the AcCENT Pieces

A pocket square, a subtle chain, a sweet pair of shades: Accessories can make the outfit—but, and this is the crucial point, only if you maintain some restraint.

Just don’t go overboard or you’ll get a Jersey Shore vibe.

Jewelry is a privilege, not a right, and men who abuse this privilege pay for it by looking totally inexperienced, or, worse, hopelessly tacky.

“I love a casual watch, ring, or bracelet. They can make an outfit distinctive,” says Moore. “Just don’t go overboard or you’ll get a Jersey Shore vibe.”

But jewelry isn’t the only accessory you can use to show the world that, yes, you are an adult man with adult man tastes and preferences.

“You can also play with monochromatic looks and tonal palettes,” says Heyward. “Try an indigo sports coat over a pale lavender thin-striped dress shirt, paired with a navy and purple tie. You can also experiment with things like cufflinks and pocket squares. I also encourage my clients to layer with scarves in the fall/winter.”

Sounds classy. Anyway, here’s the point: If you’ve clawed your way through adolescence and made it, scarred and panting, to the shores of true adulthood, you may as well dress like it. And there’ll be no need to raid your dad/grandad/uncle’s wardrobe if you get your own accessories closet sussed.

If jewelry just isn’t your bag, the instant way to elevate your outfit is via a scarf. Add a dress scarf to a suit for a cooler take on the tie, or inject color into a drab outfit with a bright chunky knit scarf.

FashionBeans’ Picks

The Basic: Alpine Swiss Mens Plaid Scarf Soft Winter Scarf – if you’re not used to accessorizing, gently does it with neutral gray. Wear the Alpine Swiss Mens Plaid Scarf Soft Winter Scarf loose; the stripe accent has the added bonus illusion of elongating your body if you’re on the short side.

Alpine Swiss Mens Plaid Scarf Soft Winter Scarf, $9.99 at Amazon

The Trendsetter: Calvin Klein Men’s Bi Color Reversible Scarf is a scarf that’s made for the indecisive amongst us. This won’t only inject your winter outfits with some color (in on-trend burgundy), but you have two ways to wear it. Go striped or plain depending on your mood.

Calvin Klein Men’s Bi Color Reversible Scarf, $39.99 at Amazon

The Luxe: A silk scarf gives instant grown-up status. Factor in some subtle polka dots and you’ll give a suit a (lot of) VIP edge. It’s an easy styling trick to jazz up a boring/tired suit, without going for a stiff tie.

Hickey Freeman Men’s Polka Dot Tubular Tuxedo Scarf, $107.17 at Amazon