How do I properly tighten the harness straps on my child?

Tighten the harness by pulling the harness adjustment strap until you are not able to pinch any of the harness webbing at your child's shoulder. A snug harness should have no slack, lie in a relatively straight line without sagging, and not press on the child's flesh or push the body into an unnatural position. The chest clip should be raised to armpit level after tightening. (Page 70-71)