I find after the first couple of rounds as the knitting stabilizes that it becomes automatic to place the working needle either over or under the previous needle as it feels comfortable. I find the best tip for me is to keep the stitches not being worked in the center of the needle so as you manuever around you are less likely to drop stitches.
Before long you'll feel like an old pro at it.
"Never doubt that a small group of thoughtful, committed citizens can change the world. Indeed, it's the only thing that ever has."--Margaret Mead