I keep a running To Do list with 5-10 things in it, and if I cross off two or three things, I consider it a success. When it gets too long, I stop adding to it until I can make some room.

When the items on there seem too big to realistically tackle, I start adding little ones that seem trivial but add up, just to have something to tick off and, if I'm lucky, create a sense of momentum that will spur me to keep working down the list.