Completely depends on the trick and the spot. You have the general concept though, the best way to practice is find a tall out ledge and practice getting the timing down for different tricks. The timing on a bs tail bs flip or just bs tail pop out will be different than a crook or 5-0 pop out after a while you'll figure out the timing for your tricks. Now the transfer stuff like nosegrind pop back to the side you started and shit like that, that I love doing needs the spot, timing, and getting your person to stand in the grind correctly like I didn't know if a bs crook pop over was possible on a non glitch flat bar until I approached it like how I do in real life and positioned my skater so my shoulders were pointing forward and I was standing in the grind so my toe side wheel was kissing the rail.
ALSO 40-50% is pretty good if you're doing ollies, if you're trying lazy flips, shuvs, or transfers that shit is hard and isn't every try I don't care who you are.
Good luck though and you can do them in S3!