Start by measuring the foot of the person whom the slippers are for. Usually, that means doing an outline of the circumference of the foot, and then measuring each side of the foot from the back of the heel, the instep (the arch of the foot), from the instep to the toes, from the bottom of the foot to the top of the proposed boot, and around the ankle at the height of the proposed boot. When you cut the sweater, make sure there is extra space for sewing the seams.
If you do not already have a pattern, you have two choices: you can base it on a pair of slippers you already own, or you can purchase a pattern at your favorite craft store or online.
Use your pattern to cut the pieces of the recycled sweater slippers. It is best to keep the sweater ribbing vertical; it looks nicer and makes it less likely to unravel.
When all of your pattern pieces are cut, sew them together inside out. Whether you are sewing by hand or by machine, make sure you use a thread that is thick enough to hold together sweater material. Be aware that thin sweater material may be hard to keep in place (especially in the ankle section), and thick material will most likely be harder to sew together. If you are using wool, remember that if the sweater was itchy for your arms, it will be itchy on your feet! If so, you may want to sew a liner of non-itchy material on each piece of the pattern first.
Whether you are sewing by hand or by machine, make sure you use a thread that is thick enough to hold together sweater material. Be aware that thin sweater material may be hard to keep in place (especially in the ankle section), and thick material will most likely be harder to sew together. If you are using wool, remember that if the sweater was itchy for your arms, it will be itchy on your feet!
If you are going to wear your slippers indoors only, you may go soleless, or add a cloth or fleece sole. If you plan to step outside (even if it’s just the patio or deck), it is best to add leather soles.
How to wash them? If the sweater was machine-washable in its original form, you can wash the recycled sweater slippers in the machine. If it was hand-wash only, continue to hand-wash. If the slippers have leather soles, though, just wash or spot-clean the top part and wipe the soles down.