I think that a good strategy of self-improvement is setting the bar a little bit higher than you can reach. You can achieve much with many little steps. Every step you take reminds you that you're making progress and motivates you to work.

I experienced it when I was studying mathematics. I read modern mathematics textbooks/papers at a snail's pace because mathematics is like a tall tower - in order to get to higher levels you have to climb the lower. When I looked at what I learned in a single day I didn't see much progress at all. But after a few months of learning I saw that I'd progressed much.