Not only are habits central to self-improvement, but they're also one of the best studied aspects of psychology. We have countless studies showing how the impact of association, rewards, punishments and contextual cues will have impacts on behavior.

If you're looking to dive deeper into habits, I recommend:

How can you reach a destination if you don't first know what it is? Goal-setting not only involves deciding what you want, but also planning how you should get there. It's a common theme, even if many people disagree about which aspects are most important.