Even for people who LOVE writing, there would still be times when you simply cannot write anything of use. It's like a mini- writer's block. This is true for both fiction and non-fiction writers. For me, I just recently found that I write better and, more importantly, I have the motivation to write better, when I'm cradling a Starbucks beverage. Yup, what an expensive little tool.
Anyhow, for others, this can be anything. What is it that helps you get into your writing mood?
Do you have special spot, maybe on a window seat, or outside your veranda?
Do you need to smoke, or play Minesweeper first?
Do you have a specific playlist on your iPod for writing purposes?
Give your mind as much assistance as it needs to get the words out. Think of it as oiling a machine.
For me though, as I did not go out today, I have to settle for instant cappuccino :|.