This article is from the Ballet and Modern Dance FAQ, by Tom Parsons firstname.lastname@example.org with numerous contributions by others.
There are stores that specialize in dancewear. Try the Yellow
Pages; look at the ads in a magazine like Dance Magazine; or look in the
files `mailorder.txt' and `shoes.txt' in the Dancers' Archive.
It's harder to find dancewear for men than for women, because the
market is smaller and many places do not stock clothing for men, or stock
only a very limited selection. For men's tights, try sporting-goods
stores, and remember also that tights are unisex. As long as you don't get
sheer pink tights with red spangles, who's going to know whether you're
wearing men's or women's? In cases of absolute desperation, you can try
women's non-dance tights, available in any department store--but be warned
that they're usually very sheer and look funny on a man. If you have to
resort to these, try a light color: the sheerness is not as obvious in that
case. (And beware of that conspicuous gusset or panel between the legs on
many brands that marks them as women's tights. That can be embarrassing
if you should do a cambr'e forward or a promenade en arabesque. I've seen
some women's tights by Danskin that do not have the panel.)
Buying shoes is troublesome, because it takes time to learn how to
tell when a shoe fits properly. (It must fit like a glove.) Salespeople
in dancewear stores may or may not know. It may be a good idea to show the
shoes on your feet to your teacher and get him/her to pass on them.