When I agree to a commissioned work, I give the customer hard date deadlines - it's the only way to keep myself on track and not let the project get pushed off.
I use a similar technique for my seasonal part-time proofreading/editing job with American City Business Journals. I tell my boss to give me definite, hard deadlines for editing jobs; otherwise, something more compelling will always come up.
Unfortunately, when I'm dealing with personal projects I don't do that same thing. So every time I walk down the stairs, I get a pang of guilt as I rest my hand on the 58" x 7 7/8" x 3/4" pine board (oh, I know it well...) capping a half wall that I need to replace with a mahogany board to match the hand rail I replaced last year. (Seriously, Ethan, it's just a board! It's not like painting trim! Fix it already!) I'd be less ashamed of myself if I didn't already have the replacement board in the basement.
Whenever I walk into our hearth room, the wimpy (again, pine) mantle on my prominent fireplace reminds me I promised my wife I'd replace it with something more fitting to the house and the room. And then I think about the mantle clock I said I'd make so she wouldn't have to continue her fruitless search for one in the nearby antique stores.
As I cast my eyes downward in shame, they rest upon the transition between floor and wall and I'm reminded of the yards and yards of trim I still need to paint...
Usually about that time, I feel compelled to run outside and stare at something a little less overwhelming, like the mess in the garage. But even then, my thoughts eventually turn to cedar siding and brown caulking and carpenter bee holes and unsealed driveways.
My wife has found me curled up in a ball on the floor more than once. I think I have her convinced it is a modified child's pose...