My theory is that if I don't believe in the dreaded writer's block then I won't get it!! Usually, I find if I'm stuck on something it's because the story's gone wrong somewhere and I need to go back and figure out where and why. Once I fix the problem I can write again. If I'm struggling on one project I'll sometimes work on something else instead (I usually have more than one book on the go at a time). I also strongly believe that we need to give ourselves time to recharge. I write best when I'm exercising, eating properly and getting enough sleep.