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.
make w/ felt or paper w/ pop cycle stick, young children give them heart patterns. Older kids: allow them to create their own staggered size hearts. Decorate 1 or 2 sides; don't forget to have kids sign/date