My slippers are a pair of three year old Merrill fleece lined clogs similar to this. I use outdoor shoes for slippers because I often end up outside in my robe and jammies. If it isn't the dog it's the moment I take to look at something in the garden and find I'm still out there an half-an-hour later.
After three years I needed new insoles. I hunted online and could only fine Uggs brand wool inserts but everyone wanted to charge me a shipping fee that was two-thirds the price of the inserts. You know those fleece inserts weight next to nothing; shipping just shouldn't be that expensive. I'm sorry, shipping costs for a set of new insoles is not worth a price equivalent to a ball of yarn. I have my priorities!
Then I remembered my Spinning Teacher telling us about making wool insoles out of a felting project gone wrong. An idea clicked into my brain. I pulled out a mystery yarn (looked like a Cascade yarn with some gray going through it) using a double strand I knit a 13 " square.
Felted it until it was a 1/2 " thick. When it was dry (which took two days it was so cold around here) using the old insoles as a pattern I cut out my new green insoles.
They fit perfectly into my slippers and boy are they warm. Wow, I saved the price of a scarf's worth of yarn making these myself. Now I'm looking around for other shoes that might need new wool inserts. "I love it when a plan comes together" (remember the A Team?)
Ty keeps watch on what goes on around here.