Velcro is a good alternative for doing a clasp for your project rather than a button.  It's more generic name is hook and loop because one side has the hooks and the other side has the soft loops.  It's easy, fast, and works great.  It comes in a variety of width, length, and colors, but you just need to make sure to always get the sew-on type when using it for a sewing project.  Otherwise, the stickiness will get caught up in your needle and that never ends well. Want to see a demonstration on how it's done? Then you'll want to check out this video.