Before I cut my hair, I had the same problem. I usually just kept it in a ponytail with the really thick holders. You can find them pretty cheap at someplace like Claire's... maybe even Walmart! The one's below are the ones I use... it's the first picture that comes up.
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Another thing I use every now and then is this AWESOME whirl-a-style. You put your hair in a ponytail, put the whirl on, and twist it up into a bun. It's super fast, super easy, and REALLY cute. This thing saved my butt for ballet classes at school! It's 7 bucks at Claire's.
Check it out here!
I also like to do two braids, inspired by Vanessa Hudgens a la HSM2 promo shoot. This is actually pretty easy. Put your hair into two low pigtails and secure them with an elastic. Then, braid each side and secure it at the bottom. This actually works pretty well, it keeps out of your way for the majority of practice.
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There's also the option of doing cornrows, if you think it would work in your favor. Not so much for me!
But in case you want to try it, I found instructions on Seventeen's website... I bet it would keep your hair out of your face better than any of the other ideas though!
Cornrows... here!
I hope I helped! And kudos to you for wanting to donate it! I donated my hair a few weeks ago... best decision I've made in a while!