I take my hubby's old blue jeans and mend the front part of the legs. Generally this is the only really worn out area at the knees. I use old-old blue jeans and make a large patch, I open the leg up at the seam and it makes it much easier to sew on the large patch. Hubby then uses the mended pants for his week-end car repair or just puttering outside fixing things. Get extra 'mileage' out of the jeans and especially at what they are asking now for new jeans.