Your shoes will be more comfortable than when they were new.
What a great way to start the new year!
I'll demonstrate by resoling a pair of Crocs using contact cement and foam from interlocking floormats.
Until you add tread, the new soles are almost as slippery on wet pavement as the worn-smooth crocs were.
Step 1: Flatten Your Soles
You might want to grind your soles flat with a beltsander or disk sander with the coarsest grit you can find. Instead of flat you could go nuts with amateur orthopedic theories.
My Crocs have worn down pretty flat so I'm going to skip the grinding.