A frontside is pretty easy once you get the hang of it. A good way to practice this is to skate up to objects (both high and low) and try to stall on them. As you get more practice, your body begins to learn what it needs to do to jump that high and stall in the proper position.

You also must have the proper position which is essential to doing almost any grind. You should have your feet spread about the width of your shoulders and as you are grinding the should lock together but remember it will practice but it will come.