A long time ago, I read some advice from Stephen Covey about applying effort within one's Circle of Influence to extend one's Circle of Concern. The advice is useful to remind oneself from time to time.
What are some obvious things within most people's circle of influence?
1. Knowledge acquisition (useful for careers and other things...with a normal human brain, if you study, you will learn...nowadays, an internet connection is sufficient to have fairly good instruction as well...MIT open source classes, wikipedia, lesswrong, etc.)
2. Willingness to think/brain storm/model/track one's success...the only limit is time. But long-term one can free up some time by doing modeling and trying to figure out how to waste less of it.