Clothes that have metal in their designs will most likely set off the walk-through metal detectors, necessitating that a TSA agent will use a handheld metal detector. Avoid wearing these clothes. A single metal snap on a pair of jeans shouldn't set off the detector, but an under-wire bra might. Also avoid wearing, if possible, jackets, coats or any piece of clothing large enough to hide dangerous items. You must remove these and stuff them into a plastic container that must pass through an X-ray machine. Since this takes additional time, unnecessarily wearing clothing like this works against your as you try to get through the TSA line quickly.
Passing through the metal detector with ease also requires avoiding steel-toed boots or any type of shoe that has a significant amount of metal. Even if your boots don't have metal, pack them or leave them at home if unlacing them takes more time than slipping off a slipper, since everyone must remove their footwear. But don't actually wear slippers unless you're wearing socks, as a courtesy to those standing with you in line who don't want to see your feet. Also, for this reason, travel experts from EagleCreek.com.suggest avoiding wearing sandals.
In terms of accessories, avoid metal. Metal accessories could include metal hair barrettes, body piercings, cuff links, necklaces, bracelets or any metal jewelry. These must be removed and put into a little dish that must also pass through the X-ray machine. The more jewelry you have to remove, the more time you -- and others -- will spend in the TSA line. One commonly overlooked item is the belt, which usually has enough metal in the buckle to set off the metal detector. If you must have one, remove it ahead of time and put it in your carry-on bag before getting in the TSA line, or remove it before reaching the X-ray machine conveyor belt.
Don't wear anything that even in a joking way incorporates the word "bomb" or any word that gives a hint that you're a belligerent person. Even if you don't mean any harm, not everyone will see it that way, especially TSA agents responsible for helping deter all threats. You are allowed to wear head coverings and other religious garments. But be prepared for additional screening if TSA agents think that you could hide dangerous objects in the garments or head-wear.