1.Be nice to the people on the way up,,,, up may need them on the way down. .... This goes for mechanics, crew , fellow pilots, secretaries etc.
2. I tell my F/O's ... teach me what your favorite captains are doing. Tell me what your least favorite captains are doing.
3. Listen to that little voice in the back of you mind that tells you something is not right.
4. When you get out of your normal routine , take a Safety pause and recheck everything and or do the checklist again.
5. For your career... Stay in touch and keep a data base of all your classmates and colleagues . Many jobs and upward mobility rely on networking. See #1...
Good luck.