Knitting Tutorial: Joining Stitches In the Round with a neat, easy and invisible technique. Just make sure that your stitches are not twisted on the needles before joining. GOID Idea for joining in the round Should be a better join solution.
Genius slipper design where you knit a short "scarf", fold and sew onto your bottom. Garter stitch extra chunky yarn about wide, and however many rows you need, then sew into the 2 layers of the felt bottom.