Costuming is not essential to storytelling, but the kids enjoy it, so we do it :)
I want the students to have the freedom to interpret their characters by helping to come up with their own costumes. Mostly we pull things together from thrift stores. Costuming in Elizabethan period dress is elaborate and expensive so we may never go that route. We don't have the luxury of a permanent rehearsal/performance space to erect sets in --- we travel light --- so we try to make the actors as interesting to look at as we can.
Each actor is required to have a pair of shoes that allow for silent movement onstage. Men's dress shoes are generally heavy, noisy, and make certain types of movement awkward. Girls are also required to have suitable footwear, but it's easier to come by. Acquire the necessary shoes before the first January rehearsal.
No eyeglasses with lenses in them will be allowed during performance. If you can't safely see without your glasses, then it's time to get a trial pair of contacts. The audience needs to see your most expressive feature!