It is safest for a forward-facing child to ride fully upright. Many convertible seats have both a recline and upright position. Some child safety seats allow the use of the recline position when the seat is forward-facing, but most require that the seat be fully upright.
The shoulder straps must come from the back of the child safety seat at or above the child’s shoulders.
The harness straps must be tightened over the child so that only one finger can fit between the straps and the child’s body.