Have you seen this Rainbow Loom case pattern by Noodlehead? I haven't purchased a pattern in quite a while, but went ahead and splurged this time and really enjoyed this project for my daughter.
The instructions were easy to follow, and I love the multiple style cases you can make from this one pattern.
This is the inside of the case, with a vinyl pocket for your bands, or whatever...and two pockets at the bottom for your loom(s).
The only gripe I have with my case (not the pattern...she certainly does mention you can do this by hand)....is that I SHOULD have done the last binding step by hand. I quilt, I know how. And I found it difficult around the curves to match the inside/outside pieces. So, although the binding looks nice on the outside, on the inside I have this...
Annoying, when the rest of it is so beautiful! Oh well, next time I know. And I'm sure there will be more!