Cowboys and Indians are the central figures of the frontier mythos which plays such a large part in the American imagination. These archetypes make fun and easy costumes for all ages. Many of the basic ingredients of a cowboy or an Indian costume are probably already lying around your closet or jewelery box, and you can find the rest in a neighbourhood thrift store or a toy store.
The gunslinger is a classic Western figure, and one of the easiest cowboy costumes to make. Start with a pair of blue jeans and a button up Western shirt, along with a bandanna to wear around your neck. Add a leather belt, preferably with a thick belt-buckle and a vest made out of suede, denim or some other cloth. Add a brown hat--or if you want to be a bad guy, a black one--and a black trench coat from a thrift store. Put on a pair of cowboy boots (sturdy hiking boots will do in a pinch) and two toy guns at your hips. Alternately, modify the costume by wearing a fake bowie knife or carrying a toy shotgun.
Cowboy, Cowgirl or Sheriff
The Western gunslinger look can easily be modified to look more like a cowboy on a trail. Simply leave the overcoat at home and wear a denim overshirt in addition to jeans and boots. Carry a lasso on one hip and a toy pistol on the other and put a pair of spurs on your boots. To go as a Western sheriff, get a sheriff star and wear a white hat. Put on a bolo tie and (if you are a man or want to look like one) a fake handlebar moustache for a touch of Wild West authority.
The classic "Indian" costume so famous in old Western movies begins with feathers. Stick a single feather in a headband, put feathers in your hair or glue several coloured feathers to a strip of cardboard, glue a strip of fake hide over it and tie it by fastening yarn to the back. Put on a pair of leather trousers, or just wear tan corduroys and a loosefitting tan shirt or blouse. Alternately, wear a tan dress. Put on moccasins and wear beads or coloured bracelets for accessories. You may carry a bow and arrow, knife or rifle as well.