Practice, Practice, Practice - You need to do a LOT of nudging to get the hang of timing, and what works.
--- From your comments, I believe this is the most important aspect for you.
As far as outlanes, think of it like you are decreasing the size of the vertical space the ball can escape (when you nudge up).
Only nudge up if the top of the sling or post is close enough to touch the ball (with the nudge). If the ball is on the high side of the open space, do a slap save or side to side nudging instead. Also, you need to have enough practice to identify where the ball will be a split second ahead of time -> most people need to practice EARLY nudging, because most novices are late most of the time.
