I've come up with a way by messing around with the legs, but that only gets me about two steps. How do you pros do it?

You can find tutorials on YouTube.
http://www.youtube.com/watch?v=UsLquVtVl_k

^ Thats a good starter that Fyerr gave you, but most people that run professionally have their own run, or have a diffrent run than that run, some people have gone on to do relax runs which are slightly harder in my eyes due to the balance and speed, and ofcourse, how to get yourself forwards without falling over (backwards and forwards