So I have some shoes which although flat, are quite hard on the soles of the feet. I tried putting in some insoles, but they were a bit thick and made the shoes a lot tighter.
Then, I spotted this:
This is a sheet of that bumpy squishy plastic that is used to wrap electronics. My thrifty self thought it might work if I cut out a sole shape.
Voila! Sooo comfy! The shoes felt like new Docs! You can see after a day of use how they really cushioned the feet. And they don't eat up all the foot room. Very pleased with this cheap way to add instant air pillows to my shoes. And a way to re-use/recycle too!