Solon’s advices

Trust good character more than an oath.
Do not lie.
Pursue worthy goals.
Be in no hurry to make friends; but once they are made, do not discard them.
Command only when you have learned to be ruled.
Give the best advice, not the most pleasant.
Make reason your guide.
Have no dealings with base men.
Honor the gods.
Respect your parents.

Diogenes Laertius - Lives of the eminent philosophers