How to Make Snuggly Slippers from Old Sweaterscomments (19) February 22nd, 2013
Then I went around a second time with a three-step zigzag (set at 7mm wide by 2mm long), sewing both layers of seam allowance down to the sole piece. This will help reinforce the seam as well as keep the edges from fraying.
4. Crochet the edges. Make a slip knot, and join the yarn onto the heel edge of your slipper with a slip stitch.
I used a size G hook and two strands of fingering-weight yarn. Chain two and work over the edge with one single crochet, chain one, and repeat around. Be sure to pierce the slipper at least 1/4 inch down from the edge to get a good hold on it, or the crochet will pull off eventually.
When you've gone around once, join to the second chain with a slip stitch, chain two, and repeat the same stitch pattern, working your single crochets into the chain-ones of the previous round. Repeat for the third round, but leave out the chains between every second stitch on the front third of the slipper, around the curve at the toe end, to decrease. At the end of the third round, finish off.
5. Make the strap. Try on the slipper to determine where you'd like to put the strap across. Also measure how long it needs to be to go across your foot and hold the slipper on. Join on yarn with a slip stitch at one of these points, and chain across the length you determined. Join at the other point with a slip stitch, then slip stitch again one stitch over from join, and single crochet back across the chain. After working into the last chain, join back to the starting side and finish off. Weave in the ends.
Wasn't that easy? I might stitch some suede soles onto the bottoms for added longevity. You could also make the sole piece two layers thick. And just think of all the ways you could embellish these, and how fun they'd be if made out of striped or patterned sweaters! I don't think my toes will ever be cold again.