I try not to get overwhelmed and focus on one task at a time until everything is done. I find that once I've started, I get very into whatever I'm doing and have no trouble finding energy to continue, it's just that initial push. So, as others have said, it's all about initially pushing yourself to do what you "don't wanna"!
(having kids helps, as so much of life's less pleasant tasks can no longer be put off or ignored, you live for someone else on a minute by minute basis.)
The more I see the less I know for sure.