I believe this is probably the number one run stopper for most players.
One thing I've noticed is ... when you're shooting off the rail and your cue isn't perpendicular to the rail, when you follow through, if you touch the rail, it might deflect your cue off line.
Aside from that, and some people's suggestions of looking at the CB last... who has some undeniably good drills or tips for shooting elevated?
Thanks
Taught to me by Jimmy Reid 25 years ago.
Stroke over the cue ball and on the last stroke go lower and hit the cueball. This stops you from focusing too much on the cueball when jacked up. It works well for me.