The art of Standing on PC's.  In my opinion, it is easier to stand outside on PC's vs. trying to stand on your trainer.  The reason comes from the high resistance and pressure you have to constantly keep on your pedals.  I actually use an 11x23 rear cassette to make sure I do not run out of gears.

The art comes from being in the right gear, starting to stand on either right or left foot on down stroke and correct pressure all at the same time.  Then from the standing position you continually try to dance on the pedals.  Pulling up hard and pushing down with a great deal of force.  An easier way is using a hill to help with the continuous pressure. If you can stay in the correct gear with the correct pressure, vwalla!  Now your standing on your powercranks!

The first time I did it, I was screaming for joy and then I almost crashed, don't do that, stay calm.  Just know you have made a huge accomplishment.  In my opinion only a small percentage of people have accomplished this task.