One day I was in the coffee shop with my friends, and after five years of not drawing, I had the urge to pick up a pencil and start drawing again. Only, I didn't have a pencil. All I had was a fine point pen. So, that is how I began my pen-style drawing. No ability to take back the marks I made; all that was left to do was to simply draw.
I also work with graphite and charcoal which is a bit more forgiving. Let me know which speaks to you most!