plan out when I'm going to work, and how much I want to get done, then start. That sound almost silly, but the key to writing really is in actually doing it regularly and to keep going without worrying about small errors. Writers block seems to me to be all about second guessing yourself, which should be done, but not while you're trying to get a story down. That's what editing is for.
So that's the physical part, as for story ideas, well, that just comes to me. Constantly. I probably have around ten thousand good story lines in my head, ready to go. It's particularly easy once I have a character already established, but it happens all the time. Almost everything I see or hear triggers one. (Why, yes, that is as annoying as it might sound...)