If you are talking about "straight airs" you want to get the tail of the board to spring you a bit extra off of the lip.
Depending upon your riding ability there are two ways to do it. If you are an experienced rider and have a good ollie, then slightly driving or shuffling the board under you right at the lip will load that tail similar to an ollie and pop you. If you keep your core locked and you are compact in the air you can then pull the board back under you. It's a great feeling movement but don't try to pop straight airs this way unless you "get" what I'm talking about.
Otherwise time your pop so that as you are "slightly" hopping evenly and with an engaged core at the lip, if the tail still manages to catch the end of the jump, you will feel the tail boomerang you a bit. Keep you core locked so that your body doesn't extend and get tall.
And as Extremo mentioned, you probably won't feel any of this unless you are hauling ass and hitting a medium sized kicker at a good speed. ZOtherwise with all that dinking around on little stuff it will be hard to get gravity and board mechanics really kicking in.