Brandon Gene Petit
Every time an idea for a poem or a line comes to me randomly, I scribble it down on a notepad beside my bed or jot it down in my iPad so I don't forget it later. This way, whenever I sit down to write I have a plethora of varied fragments to choose from, and I can just pick one that fits my mood or fancy and then start expanding on it.
I also have several pieces going on at once... I never feel obligated to work on any one particular piece when I'm not "feeling it" at the moment; I can always "jump around" at will. This keeps me from feeling forced or limited... instead of trying to narrow my focus down, I just feed my ADD-tendencies by supplying any whim, and the book gradually comes together overall.