lean back a smidgeon, while approaching the lip
as your coming up on the sweet spot of the lip for nollies, your going to shift you weight forward
the thing about nollie-ing off jumps is that your pop is actually earlier off the jump than it would be if you were just hitting it with-out nollie-ing
so your going to need to fudge around with where you pop for each jump with nollies, but when you can actually find the nollie pop, and commit to it, you can actually get more pop then you normally would, shit's juice!
good luck!