Another thing I do, which helps me get my fat ass out the door, is to be well organised. For example, this morning I've been doing my filing, updating, printing out stationery and sorting the van, so come tomorrow morning all I have to do is make our sarnies and head out to work.
When I print my stationery, I normally do about four months worth. Updating I try to do everyday I work, but Friday evening I just binned the van and everything; hence I'm doing it today.
Getting new work always helps motivate me too.