Fortunately I had equipped myself ahead of time with a supply of shoe goo, and still had plenty of scraps. A little bit of cutting and gluing made them well enough for walking again.
Things to try differently:
- Use a marking pencil to trace the patches onto the sole, so I know exactly where to spread the glue without putting sticky pieces together.
- Do this at a table covered with paper.
- Make sure the patches are covering the entire weight-bearing part of each foot pad they are under, so I don't feel the edges.
- Use a knife to taper the patch edges slightly.