Twyla Tharp in her book, The Creative Habit, talks about how helpful it is to establish some rituals - automatic, but decisive patterns of behavior - at the beginning of the creative process when you are most at peril of turning back, chickening out, giving up or going the wrong way. The ritual erases the question of whether or not you want or like to do it, you just do it.
Do you have any rituals that get you started or can you think of any that might work for you?
I use the kitchen timer, telling myself I will spend 15 minutes on something...and usually I'm enjoying it so much, I spend much longer. But it's a way to get started which is the hardest part.