Harry Potter Gifts for my Friends?:)?

So my friends and I are HUGE Harry Potter fans, and we're all going to get each other HP - themed gifts for our birthdays/Christmas :) I was wondering if anyone had some good ideas as to what I could get them? I'd like to do something handmade so that it's thoughtful, but also something that they'll enjoy and not fall apart:P I'd also like it not to be super expensive like over $20 or so ...:) If it helps, we're all three girls. I'm "Luna," one is "Fred" and the other is "George." Thanks :)