Keep the strop taut. Go slow, fluid. Roll the edge over the spine before you get to the end of the strop and start moving back before the edge touches down.

Add no pressure but try to feel the draw of the blade if you can (some strops don't draw).

Its better at first to do light/ineffective stropping because razors actually don't need to be stropped every shave. They get out of alignment after about 3 shaves. That is NOT to say that you should strop every 3rd shave, but rather that by stropping lightly you are doing enough to maintain the edge. The razor should never feel like its rough simply because you didn't strop perfectly for one shave. Don't assume that by stropping more or applying pressure that you'll suddenly learn how to shave and get a better shave. Its almost never the strop that is the problem.

It is, on the otherhand, often poor stropping that becomes the problem.