Use only shredded, dry leaves and garden waste. Don't use kitchen food scraps. Add moisture and 21-0-0 fertilizer, cottonseed meal, or blood meal mixed throughout the bag. It would help to add a small amount of garden soil to provide organisms to promote breakdown and cut some holes in the bags for oxygen exchange within the bag. Place bags in full sun and turn bags every few days. This is not the best way to prepare compost.
For more and better options, read: Don't Bag It™ - Compost It!!