I bought a cable knit sweater from Goodwill for about $3. Here's a little tutorial for how I turned it into some super cute boot socks.
Step 1: Cut sleeves off. **This could be your only step if you want! Just wear your socks with the cuff side on the top side of your boots. For me, I wanted to hem the bottom part so they wouldn't fray. However, I don't sew, so this is a no-sew way to do it. I used Heat n Bond, which I had on hand. You can buy this at any craft store.
Step 2: Turn the sleeves inside out and cut your Heat n Bond to the length you need.
Step 3: Follow the directions on the Heat n Bond. It says to place it on the fabric with the paper side up and press your iron to it for about 2 seconds.
Step 4: Fold your sleeve over to make a hem and then iron as the directions say (press iron for 8-10 seconds to seal the bond)
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