Stretch before you go out. Makes you more in control or where your body is!
Hold the rails until you are on your feet.
Don't think of it as a "pop up", it's a slow smooth movement, seen how good surfers push them selves up, wait until they are in a good position in the lip and then only stand up when they are making the drop. Do it slower and smoother but don't make the mistake of trying to stand up at the bottom of the wave, you stall and bog down.