I recycled my shrunken wool J. Crew sweater :(  into some new slippers for Sal :). I took apart his raggedy old slippers to try to salvage what I could and to trace the existing material to make a new pattern.  I took out the foam insert, washed it and used it as a guide for the shape of the sole pattern. I added a seam allowance to the traced pattern and then cut it out of the sweater. I cut open the sleeves for the top parts and used the front of the sweater for the foot beds. I stitched on a piece of nubuck leather left over from my peasant booties onto the sole to avoid any super slippage and used tan wool left over from making Timmie cocoons for the lining. I added some more padding to the foam inserts with these:

Easily available at pharmacies, and saw them here for 99 cents.

I left an opening by the toes to slip in the foam insert and then flipped it inside out and hand stitched it closed.