What to wear
When competing it is essential to have good shoes--they should slide on the floor, look nice, and fit tightly. Ballroom shoes are typically between $90 and $130, but you can find lower priced shoes online. If you are interested in buying shoes, you should ask some comp team members about getting cheap deals online and about choosing the right size & style. Some common brands are: Capezio, Bloch, Very Fine, Freed, Supadance, and Stephanie.
For guys, dress shoes with leather soles or jazz shoes work, but ballroom shoes with suede soles are ideal.
For girls, character shoes may work, but ballroom shoes are much better, especially for Latin.
Wear black dress pants and black socks. Wear a long-sleeved white dress shirt for Standard and a black shirt for Latin. Make sure the shirts don't bunch up at the shoulders when you raise your arms, and try to have the Latin shirt be fairly close-fitting.
For Standard, wear a long-sleeved fitted top and a long skirt (mid-calf to ankle length). For Latin, wear a short skirt (mid thigh or shorter) with shorts underneath and a tight-fitting top. Asymmetrical skirts tend to look good on the floor. It is also best to either wear skin colored tights or put makeup on your legs for Latin. For both Standard and Latin, hair should be neatly pulled back. Longer hair should be put in a bun. Make-up should be done to the extent of stage make-up (but not clown make-up), including foundation.