Slack
You cannot move a hook through bone with a bow in the line. Reel down until you feel the fish, then set. The reel does the work, not your shoulders.
Sharp
A point that will not catch on a thumbnail will not catch in a jaw. Check after every fish and after every rock.
Angle
Set to the side, not overhead. A sideways set drives the point into the corner of the mouth. An overhead set pulls the bait straight out of it.