printable PDF of this pattern now contains a “ruler” to guide your hole poking. The ruler helps ensure you have the perfect number of holes to achieve the gauge regardless of what size flip flop you use.
Dress up plain flip flops with paracord. Use the same method that you'd use for a bracelet, but use the strap of the flip flop for the center. The tutorial in the attached link shows how to make them by completely removing the strap.
How to Crochet Boots with Flip Flops - Free Pattern + Video Tutorial
DIY: Old crocs into crochet boots - CROCHET. I don't think I'd cut off the top of the croc, but this looks like a good way to take them from "practical, yet hideous" to "practical, a little weird, but lots of fun.