I'm on a SB/510, but I bet the answer's similar-- you need to keep that atomizer wet without flooding it. It took me about two days to really figure it out.
I drip, so I put 3 (or sometimes 4) drops directly into the atty or 4 drops into the 510's cartridge. I attach the cartridge to the atty, keeping it parallel to the ground and take a 1 second drag or so. That seems to suck the juice from dripping out the bottom. Then I go to town with 1 - 3 second drags until I get the slightest hint of dry atty.
Repeat.
Once I got the hang of it, I can tell before I get to the 'off' drag. That way I don't have to taste anything but liquid nirvana.