There are so many things you can do with rubber foam, a material used on flip flops. Among them are rubber stamps, a floating toy boat, or maybe some puppets. I made some letter blocks.
Here's a tutorial in making letter blocks from worn flip flops:
1. Thoroughly clean your flip flop. Then remove the sling bands with a cutter, set them aside for recycling.
2. Draw or trace some letters with pen. If you are having a hard time here's a tip: first, print some big letters on paper, then lay them out over to the piece. Trace with your favorite pen, then enjoy some sandwhich.
3. Cut the letters separately in blocks so you can cut them easier one by one.
4. Here's the tricky part: cutting each letter with the rubber foam is quite hard especially the curved part. I suggest to cut their outlines first with x-acto knife or cutter. Always be careful when using these sharp tools. Take your time. Then use some carving tools to scoop out the "fillers." Don't worry if you carve them a little unevenly, it's part of the rustic look.
5. Once you're done cutting, you can sand the surface a little to smoothen and clean. You may also color if you want. Use them to label your mail box, pet house, storage, or wishing board.
Congrats! You've made mother earth a tiny bit happier, a step at a time.