You definitely just need to ollie the fuck out, and come at an angle. The more mellow the ramp the more you need to ollie to get back in.
Also ollie using only you legs (mainly back leg), don't whip your upper body and hands to get air. This way right from the moment you pop you have your upper body and arms relaxed to just balance and guide it around back into the tranny. It feels really weak and shitty at first, before you get used to popping only with you legs. Last thing is I think you need to have a reasonable amount of flexibility to open up you knees as you turn backside, so that you can kinda float the board "in between you legs" (sounds stupid, but I don't know how to put it into words better).
That's how I've figured them out, hope it helps. It's one of the first tricks I lose if for some reason I stop skating even for a couple of weeks.