Determine the kind of uniform you want. If the uniform is to be used for classes, rehearsals and performances, it should be basic and easily cleaned. If the uniform is to be used for performances only, it can be more elaborate, as it will not need to withstand frequent wear.
Determine what style of dance will be performed in the uniforms. If the dancers are ballet dancers, the uniform must be suitable for ballet. If the dancers are going to perform a hip-hop routine, they will need to be able to move easily and feel that the uniform matches their style.
Ask what look you are going for. Do you want the uniform to look like dancewear? Should it look like streetwear? Do you want all of the dancers to look the same?
You should also consider the conditions the dancers will be performing in. Do the dancers need to be kept warm while performing outside? Will they be too hot?
Compare what you want the uniforms to look like with your budget, and determine whether you should make the uniforms or buy the uniforms. Regardless of whether you choose to make them or buy them, you should browse several dancewear catalogs and websites to get ideas. Once you see what other groups are wearing, you will have more ideas for your group.
Make or order your uniforms. Take great care to ensure that each dancer gets a uniform that fits her well, flatters her, and is easy and safe to move in.