I've been trying my hand at loop passes on Metallica and failing miserably.
I'm really working on something I see Bowen doing in his tutorials, but I don't know what it's called. When the ball is barely reachable with the tip of the flipper, he'll time it perfectly and throw it into the other inlane and trap on the opposite flipper. Previously, I was flipping both flippers in rapid succession, but his way doesn't throw the ball out of control.
I can get it right about 25% of the time.