Last year I heard a successful, retiring, Canadian pastor (Laurel Buckingham of the Wesleyan Church) speak on self-discipline. One of the disciplines he talked about was the discipline of the "can-dos."
He shared 4 things that are easy to do that contribute to the success of many successful people. There are certainly more keys to success than these 4 things, but these cannot be neglected.
He said most successful people do all 4 (or at least 3) well. Losers (my word, not his) are proficient in 2 or less.
1. Be on time.
2. Do what you say you're going to do.
3. Finish what you start.
4. Say "please" and "thank you." (i.e., be appreciative)