I have talked about this great pattern from Patons Yarn... Sock Monkey Slippers. The first ones I made, I hand sewed ultra suede to the bottom to stop slipping in the slippers and increase durability. This recent pair, I decided to knit an extra piece of garter stitch in the same wool, rectangular around the same width and length as the slipper. The intention was to cut a sole for the slipper that would be sewn on separately for extra thickness.
I felted it along with the slippers and ears, and after felting, cut it into left and right soles. Then I cut ultra suede soles to match ....
and with the sewing machine, attached the suede to the felted sole. Then I attached the whole piece by hand with thick thread, to the bottom of each slipper.
Softer under foot, and non-slip. Even better than the good thing they were!
My view... happy feet!