Incredibly simple
skateboarding trick. So simple you don't even have to know how to
ollie (unless you are trying this on
vert then you must know how to ollie and it is quite
difficult).
This is best learnt immobile. Simply reach down with your right hand if you are regular or your left hand if you are goofy, and grab the board in the centre (like an indy grab). At the same time take your front foot off the board and place it on the ground. Proceed to push down on the concrete with your front foot while keeping a grip on the board. Once you've started pushing you can jump at any time (start low when starting out) and pull your front foot back onto the board to land.
Once you are good at the trick fully extend your leg before jumping to get more height. Once you are good at that, as you rise tuck your back foot close to your chin for even more height (not too close or you'll hit your chin).
The vert version of the trick is identical, you simply have to take into account that you are vertical and are on a much more slippery surface than concrete, so be very cautious. Also with the vert version, unless you want to exit/transfer from the pipe then you have to lean back (not too much) and not forward.