Seriously, from experience, i know that the 2 foot jump is kinda tricky because if you try and make too much of a loofy step you loose the correct ``grip`` given to you by the reactive forces. The idea is to perform 3-5 fast (then relax) counter-movement jumps and then do running jumps x N. Your run-up has got to be as fast as possible. The first few weeks you will be clumsy, but after a while your take-off will become easy and efficient and you even will be able to add some effect to it by pushing off the balls of your feet at the last moment. (Took me a while to get it right, but once i was on track, within 2 weeks of practicing 4x week, i was jumping effortlessly everytime.
As for the 1 leg vertical it pretty much is the same, we saw vince carter and other ``strength jumpers`` plant their leg way in front, but really what you need to practice is a fast run-up and lock of the jumping leg, let it fly. Again, thrive to go as fast as possible to really sink the correct technique, believe me, it is the only way.
Pce
