The small details of chefs' jackets vary, but they all have one thing in common: The coats are double-breasted. Whether you get your chef coat from a costume store or buy one from a restaurant uniform store, it must have two rows of buttons going down the front. A traditional coat is white, but modern chefs do wear different colors. The sleeve length can be short or long.
Loose-fitting pants with an elastic or drawstring waist are standard chef garb. Dark colors, such as black, are traditional because they hide stains, but white is sometimes worn. Black and white checks or stripes are common patterns for chefs' pants. You can find complete outfits in a costume store, but if you're putting together one yourself, sweatpants work perfectly.
A traditional chef hat is the most distinctive part of the uniform. The classic hat is called a toque and has a fitted band around the forehead, while the top is over-sized and floppy. You will likely need to find a toque in a costume store or restaurant uniform store, but you can make one from paper. For a trendier look popular among many younger chefs, go for a head wrap, which you can buy or make with a bandana. For a really casual look, use a dark baseball cap.
Real chefs don't wear sneakers in the kitchen. Clogs in a dark color or sturdy closed-toe shoes are the most common footwear. Dark colors, such as black and navy blue are usually worn. Because you're just putting together a costume, black shoes of any kind will do.
Two accessories will complete your look and are easy to create without going to a costume or specialty store. Wrap a white apron around your waist -- no longer than knee length -- and tuck a dish towel into the top. If you're going for a traditional look, wrap a neckerchief around your neck with the point in back and tie it in the front. A dark or white bandana will give you the look you want.