I do these all the time. They are one of the most rewarding things I do. It's hard to make the first few cuts from the
perfectly good clothing but I remember how special and what wonderful memories they will provide. I usually make simple squares and sew them in rows, nothing fancy, just so that each piece will be large enough to recognize. I also like to cut out squares that include a pocket (sometimes with a name - like a work shirt has.) I have used shirts, pants, aprons, running clothes, T-shirts and even gloves from the NY Marathon. It turns out to be a priceless gift.