when you cross the eddyline with your butt it helps me to look downstream and brace off that paddleblade which also helps initiate the stearn.  There is a sweet spot in different eddylines to initiate due to different levels,currents,etc. The more you do them looking for the sweet spot and concentrateing on your brace you start to hit em without thinking about it.    When you get cofortable  balanceing the movement on that brace you can stall it or do screwups.  Good luck to you man.