A few years ago a mom made end of the year wish bracelets for my son's class (here). I loved the idea so much, that I stole the idea. I raided by scrap pile and found some twine, so I only had to buy the star buttons. Since I had a coupon, I bought 25 star buttons for $1.25. That makes them a grad total of 5 cents a piece!
You could even go all out and make them super fancy, if you don't have a million end-of-the school things to do. Since my life is crazy, I went with printing the saying out on my computer and gluing them to random scraps of card stock.