Ummm... think of a treat you would like to give yourself but don't allow yourself to have it until after your work is done?
Sometimes that works for me and sometimes it doesn't. Guess it just depends on how badly I want something. LOL My best treat to myself is peace of mind. I get that when I get a tedious job out of the way.
Don't beat yourself up, though, if you don't make it. Just tell yourself it's okay and you'll do better next time.
Good luck!
__________________
Psalm 119:105 Thy word is a lamp unto my feet, and a light unto my path.