You tend to become like those you regularly associate with.
The power of association is undeniable. Parents watch who their kids hang out with because they know their kids will tend to become like those they spend time with. If your closest friends are into fitness, you probably are too. If you want to get better at golf, hang around people who are better than you at golf. You will begin to adopt the attitudes and habits (good or bad) of those you share time with.
In that vein, one of the easiest ways to improve your association is by reading books. In general, I would recommend anything by Dr. John C. Maxwell, the foremost author on Leadership today, and anything by Patrick Lencioni. Lencioni typically writes in parable form which I find particularly interesting to read.
Also, the following is a list of books I have read and personally recommend
- How to Win Friends and Influence People by Dale Carnegie
- The 21 Irrefutable Laws of Leadership by Dr. John C. Maxwell
- Death by Meeting by Patrick Lencioni
- The Three Big Questions for a Frantic Family by Patrick Lencioni
- The Richest Man in Babylon by George S. Clason