If I ever compile the lessons I've drawn from years of blunders, the multi-volumed work will include the following:
Beware of apples and oranges. False comparisons rest at the heart of most fallacious arguments. A great many of the examples assembled to support a point are not the same.
Do not underestimate the role of fatigue. Basic rule: when you are tired, you will make mistakes. Get some serious sleep.
Avoid vexatious people. This comes from a line in Desiderata and it is dead-on. The haters and trolls are not worth your time.
Slow down to appreciate the nature of your work and to enhance its quality. It is far more refreshing to be a craftsman than an assembly line worker.
Read a wide range of opinions and especially seek out those in disagreement with your beliefs. See if you can find something worthwhile in their reasoning.
Lower your expectations. If you expect others to be angels they will disappoint you. You should also have reasonable expectations for yourself.
Don't keep score as to who gets what. If you do, you'll frequently conclude that you were shortchanged.
Beware of what your job is doing to you. More people worry about what they eat in the morning than where they go in the morning. Consider whether your job is building you or destroying you.
Don't believe in magical solutions. We dream of elevators while trudging up stairs. We need to enjoy the climb, realize that we've arrived at the right floor, or move to another building.