1. Cut your pieces into strips. Mine ranged from 1 inch to 2 inches depending on the thickness of the sweater (1 inch for thicker ones, 2 inches for thinner). You may want to make a test swatch before you cut up all of your strips to check the gauge and thickness of your fabric. Cutting thinner strips yields more square footage, but you’ll want the bed to be nice and thick so it’s comfortable. See what works best for you.
2. Begin crocheting the circle. With a jumbo hook, chain 2, then make 5 single crochets into the second chain from the hook.
Do not join but continue around, increasing every stitch for the second round, every other stitch in the third round, every third stitch in the fourth round, and so on. Work in this manner until your circle is the size you want the bed to be. (Note: When working with sweaters, I join by simply overlapping two strips for a few inches, twisting them together, and continuing on with the new one. The joining method I used in the T-shirt rug project doesn’t work so well for sweater knits.)
3. Make the sides. Now you can stop increasing, and work the next round even (one stitch in every stitch). Working in the front loop only for the first round of the sides helps create a sharp turn where the bottom meets the sides.
Work several more rounds, until you have achieved your desired height (after the first round of the sides, revert to working in both loops). When the bed is tall enough, work a few slip stitches to blend into the edge, and finish off. Weave in your tails.
Optional: Make a pillow. Use some more sweater scraps to stitch up a pillow for the bed, and stuff with poly-fill or still more sweater bits. You could also crochet another flat circle piece to cushion the bottom of the bed. Your choice!
Now find a sunny spot for the bed and invite your best friend to try it out!