For attire I've seen mostly navy show coats (or variation on the generic navy like windowpane, etc.), white or similar light-colored show shirt. Tan or greenish-beige breeches in most levels, some riders in the Maclay and higher levels of equitation will wear white breeches, but most of the equitation riders have tan or similar. Black or brown leather belt, nothing too eye-catching. Black gloves and, of course, a helmet :).
Tack is like most other shows- close-contact/jump saddle, leather girth, fitted white fleece/sheepskin pad or a half-pad, but a fitted pad is classic. You see both snaffles and pelhams in equitation and hunters, so whatever (legal) bit your horse goes in for shows works. Then martingales or whatever your horse needs. For equitation you see leather open-front boots and sometimes black polos. Hunters, no boots, and in jumpers generally open-front boots like Eskadrons or similar are popular.
Braiding is just the generic hunter braids and a tail braid- some people do the pinwheel in the tail as well. This is for hunters and/or equitation, by the way.
Hope this helps!