What is the proper way to secure my child in the car seat?

Place your child in the carrier with their bottom pushed back and back flat against the seat. Insert the buckle tongues into the buckle until you hear each one click into place. Fasten the chest clip together and center it on the child's chest at armpit level. Pull all slack out of the harness system starting with the webbing around the legs and moving up toward the shoulders. Make sure harness straps are snug and at or just below shoulder level, with the crotch strap close to but never under the child's bottom, and waist straps close to but never under the child's legs. (Pages 87-91)