One tip for fs shuvs that I haven't seen mentioned yet is that you really have to suck your back foot up after you pop. Focusing on that helps me pop them higher, and not scoop them too hard. If you're having trouble, try jumping backwards (behind you) a little bit, and position your back foot so that the ball of your foot is in the center of the tail and angled a bit. You can also move your back foot a little off-center towards the toe side of your board. They won't pop as high, but that makes the trick a little more manageable while you're learning.
Any tips on not sticking immediately on fs tailslides would be appreciated. I can get into them fine, but can't stop myself from coming out too soon and not sliding.