The thing is, it doesn't bother me much that I never do stick with them in the really really long run. The fact that I occasionally do them is enough to get me to do more things than I would otherwise, so... great.
Anyway, my latest scheme is at least producing pretty graphs, so that's something:
The "scheme" is just the most bluntly simple gamification you can imagine. I think up things I should do, put them on the TODO list for a particular future day, (this idea, stolen from the idea of '43 folders', has turned out to be really effective - even fixing a totally arbitrary day ahead of time is much more ominously NEED TO DO THIS than just having a floating todo item that could get done at any point in the future) and score one point for each completed thing. I give myself fractional points for things fractionally done. My current psychological interpretation is that having more things I plan to do is good as well, but the main score is number of (arbitrarily measured) things done.
Example things are, like, clean up the kitchen area, mail that annoying bill, write up that math thing I thought of, do some exercise, make some progress on doing my taxes, etc.