Sorry--I also haven't tried it myself either. /QUOTE]
Frankly I'm a little surprised. I was counting on you.
Just read a book about the Tarahumara Indians of Mexico's Copper Canyon (famous for their ultra-running skills). They make running sandals from old tires... ("Born to Run", by Christopher McDougall
Great minds think alike. I just finished the book and it was the inspiration on finding out how to make them. I now also exercise more bare foot too. Not running yet but walking stairs, doing steps and 15% on the treadmill slow.
So while I can't give you any specifics on how to do it, I assure you that many have done so and, properly done, they are very serviceable.
Come on man! Who's going to make them first. I'll be keeping an eye open for a tire that isn't steel belted so I can cut it easier. All tires are tough, I don't think I need steel belted sandles.
Think of it as a science experiment.