It’s a cliché that men don’t know how to dress. But being a cliché doesn’t make it less true. Many of us don’t know what the hell we’re doing when it comes to fashion.

Maybe our biggest mistake: We look at what other dudes are wearing when deciding how to dress. Instead, we should ask the ladies in our lives to help us out. The first thing your girlfriend or gal pal might suggest: Lose the jeans+tennies look.

That advice was one of the top-eight replies to a recent eBay survey on men’s biggest fashion faux pas.

“The running shoes and jeans thing kind of screams nerd,” says Colleen Bayus, a D.C.-based personal stylist and fashion consultant. That’s not necessarily a bad thing; going “nerd-chic” is acceptable in some contexts, like if you’re walking the dog or headed to grab a coffee Sunday morning.

In all other situations, consider swapping those sneakers for, say, a pair of driving loafers, Bayus says. “Drivers are popular right now, and a major upgrade over tennis shoes.”

Here are the other seven fashion mistakes guys make that drive women nuts, along with tips to remedy each of them.

Your “I’d Hit That” shirt with the piñata may occasionally get a laugh. But make no mistake: funny and cool are not the same thing when it comes to your duds.

“If you’re out of college, these don’t really speak to your maturity,” Bayus says of ironic or funny slogan T’s. Her recommendation: Plain T’s in solid colors. “If they’re faded or a little worn, that’s fine,” she says. “Just avoid the super-tight look, which is, again, a little immature.”

We totally get it. You saw some dude in a magazine rocking a polka-dot necktie with a plaid shirt, and he looked boss. But mixing patterns “is an absolute art,” and one that’s really hard to pull off, Bayus says. You’re a lot safer pairing patterns with solids, she says.

“There’s nothing better than a man in a nice suit, but there’s nothing worse than a man in an ill-fitting suit,” Bayus says. Unfortunately, most guys walk around in suits with pants that pool on their shoes, shoulder pads that over- or under-extend, or jackets that just don’t fit properly.

“It’s next to impossible to buy a suit that fits you well if you’re buying off the rack,” she says. That holds even if you’re spending a lot of money on a high-end number. For those reasons, it’s worth it to find a tailor who can craft you suits made to your measurements. “Plan ahead, because it will probably take them six weeks or more to make your suit,” she says. “But it’s worth the wait and the expense.”

Johnny Depp’s accessory-heavy style has caught on among some dudes. But it’s easy to overdo it with bangles, bling, and other “accent pieces,” Bayus says. Instead, stick with a single accessory—like a nice watch, or a lone leather bracelet.

“You don’t want a lot of extra fabric hanging away from your torso, but that’s what you see with a lot of men’s dress shirts,” Bayus says. Custom-made shirts are often the same price as off-the-rack options. Take the time to find a good shirt maker, and stock up on basic whites and light blues. You won’t regret it, she says.

Especially if you’re skinny, wearing the same baggy jeans you bought back in college is a major no-no now that styles have shifted toward the slim end of the spectrum. High waists, ass-less seats, and dark, solid shades are also characteristics of the “dad jean,” Bayus says.

You want to shop for jeans that fit snug but not tight, and that have a lightly distressed or faded look to them, she says. “You don’t have to spend a lot of money, but you probably will have to have them tailored,” she says. “Jeans are one of the toughest items to get right because it’s really hard to find a pair that fits properly off the rack.”

Yes, backpacks are the most utilitarian way to lug stuff around. But they also “make you look like an intern—just really juvenile,” Bayus says. A simple leather bag with a shoulder strap is a big step up—and one that’s unlikely to ever go out of style, she says.

In terms of men’s style, nothing—absolutely nothing—matters more than how your clothing fits, Bayus says. Spend time and money ensuring your duds fit your body properly, and you’ll be far ahead of most men when it comes to looking sharp.