Step 3: Wire the rubber strips to the nylon straps
I used thin steel wire as 'stitching' for the straps. Strong thread or monofilament could be used, I suppose. Because I fed the wire through by hand, ...
Improve the comfort and look of the straps for your tire sandals.
Step 1: Make the basic sandal
Follow cthoyes fine step-by-step to get the basic sandal from a tire, but skip the tabs on the sides and back of the sole. You won't be needing them. You'll find it is much easier to cut out the sandal without the tabs for straps.