This is a great mobile project since all you need is a half yard or so of fabric, a pair of pinking shears and a pair of flip flops. To start, cut 1" x 7" strips with the pinking shears from your chosen fabric or fabrics. You'll need about 30 or so strips depending on the size of your flip flops (like I'd be way more than 30 strips, but let's concentrate on the kids shall we?!)
Next, tie your strips around the flip flop band starting from one side. Make sure to double knot. Push the strips close together as you go. Keep knotting strips until your flip flop is completely fancified.
And that's it! Put on your fancy flops and head back to the pool before summer gets away. quick!