Looking professional isn’t about showing off the size of your clothes budget, your proximity to a dry cleaner, or your ability to button every button. It’s about providing the reassurance that you know what you are doing.

As this roundup of studies from Scientific American notes, you are part of the affected audience for how you dress as well, from test subjects performing better when they wore doctor’s coats to unethical behavior from experimental groups told that they were wearing knockoff sunglasses.

Even if you don’t actually know what you are doing, don’t provide the visual cues that draw attention to your blunders and make them easier to remember. Here’s a list of must-have props for keeping it professional.

A Versatile Blazer:

A solid blazer has to be at the top of the list, as it can slide back and forth from casual hang to formal occasion with ease. Some places keep a closet full of them, just for unprepared guests. But don’t let a country club pick out your jacket for you.

Pick something that fits with the rest of the wardrobe (so that you can pair anything with it) and something that fits your body. The Upcoming provides a good guide to finding the right fit.

A Shaving Kit:

A clean-shaven face can communicate efficiency and cleanliness. A well-maintained beard can mix in some gravitas. The effect of either decision is ruined if you look like you don’t know how to control your own facial hair.

Don’t show up with razor bumps on your face or raisin bread crumbs in your beard. Check the integrity of your shaving utensils and the supply of your razor bump cream, or make sure you know to keep your beard trim and debris-free.

A Second Tailored White Dress Shirt:

A white dress shirt is the basic unit of men’s dress wear. But it is also the most vulnerable. Go ahead and get a second one. No one is counting how many you own, possibly because unlike those plaid variations, it’s pretty impossible to tell one white shirt from another.

You might have just one, you might have 10 – nobody’s monitoring. To be clear though, you should have at least two.

The Right Belt:

Nothing is less professional than your pants coming off at an inopportune moment. Few things feel more uncomfortable than a belt digging into your gut. Pick something sleek and adaptable.

If you have favored belt buckles with slogans, consider pushing that energy towards throw pillows or bumper stickers. If a belt is doing its job, nobody at work should be noting your underwear. Don’t let underwear sabotage the belt’s effort by slipping up your back or forcing your hand on constant, awkward adjustment.

A Comfortable Pair of Black Oxfords and a Formal Casual Shoe:

Black Oxfords can punch up into the tuxedo class or prop up more casual work attire. Because they are such a foundational item, make sure they are comfortable. However, even if those Oxfords are uber-comfortable, you don’t necessarily want to sweat them up on a long flight or walk them over to that casual coffee you are having with a client in a park.

Just as one workplace culture’s business casual includes jeans and another marks the cut-off at slacks, so the right kind of formal casual shoe is going to vary for you. But whether it is a penny loafer or a smart sneaker, you want something that doesn’t look out of place even if you misunderstood the vibe of the event.

You can always take off a blazer or a tie to make things more casual, but you can’t take off your shoes. Pick footwear that can float like a social butterfly and doesn’t sting like a bee.

Classy Carrying Cases:

You looked sharp at the dinner. You deftly handled the conversation. You managed not to spill anything. Don’t ruin the polished effect by slapping a dilapidated George Costanza wallet on the table and rooting through a bunch of sandwich club punch cards to fish out a credit card to pay the tab.

If you are giving a presentation, people’s eyes should be on you, not straying to the frayed backpack you bought for a middle school sleepover. Invest in a subdued but professional-looking laptop case.

Emergency Accessories:

Even if you plan ahead, things can get out of hand. You were up all night working on that project and you fell asleep in your clothes. When you rushed around in a panic, you spilled coffee on that second white shirt. Good thing you’ve got that travel toothbrush, that stain pen, and those tubes of shoe polish and under-eye gel.

Presenting yourself in a professional manner is more than just resigning yourself to spending money to meet an arbitrary dress code. It’s another form of communication that shows that you can understand expectations and demonstrate sound judgment.

How you are able to work within those expectations and adapt things to your advantage can be as eloquent as anything you have written on a PowerPoint slide.