I am fully convinced that a good chunk of the writing process is actually getting your tushy in the seat in front of the computer.
Lots of people have said that you can't wait for the mood to strike, since you could be waiting for years, and I'm a firm believer in that. If you just sit down to do it, that damn blinking cursor is going to goad you into writing something, anything, and then you're on your way.
If I miss a session, or feel like I'm not in the mood to write, I start to feel fidgety - like some heroin addict in the fourth day of a seven-day detox. I've found that I just have to sit my butt down and get to work, and everything usually works out.
The hardest part of any trip is getting there, and this also goes for my computer. I don't know why it's hard to just sit down and do that stuff, but sometimes it is.
I mean, that laptop is just sitting there, begging for me to write. But be careful. That same laptop has Twitter and Facebook and all those other things made by the devil.