I have a goal, just no idea how to do it. Can you help?

Maybe this should be in the pattern section. I'm not sure.

What I'm wanting to do, is to make little hanging pouches for small hand sanitizer bottles. I would love to make something like this for all the girls at my daughter's gym. They have meet season coming soon and I thought it would be great to hang from their bags. I'm thinking kind of canister style, where the bottle would slip in, and there wouls be part of a colorful hair elastic that would come over the open top of the pouch and slide around a button to hold the bottle in place. Then there would be some kind of loop with a ring/hook end to attach to the bag.

I know it will be easy to make, but I just can't figure out a pattern. Has anyone seen one like this somewhere, or is willing to help?

thanks!
have a great weekend and a Happy Halloween!!!
lynn

Here is a free tutorial for an ipod holder, but I think it has all the details you are looking for:
http://www.bhg.com/crafts/sewing/accessories/diy-ipod-case/