look over your shoulder, pop. i had the same problems for a while. I took a break and i lost them but prctice makes perfect now dey on lock down(for the most part). try to keep your momentum going through the rail. what i mean is when you pop on you spin left i'm assuming, so make sure you don't scissor at all and keep your shoulders parallel to the rail, not facing the end of it. Keep your hands right in front of your body also, make sure they don't lag behind in your spin caus it looks un-steezy and slows down your spin like woah. and if you're not too opposed try them with no poles i find it easier. hope this helps.
"You know what would be really sweet?..........If the Loch Ness monster popped up out of the lake right now."