#1: You're responsible for code quality.
#2: Use meaningful names.
#3: Write code that expresses intent.
#4: Code should speak for itself. Less comments = less maintenance.
#5: Leave the code better than you found it.
#6: Single-responsibility code. i.e function does 1 thing well. Less arguments = better function. classes: most methods use most of the class' properties.
#7: Tests (TDD).
#8: Work on big picture skeleton, then fill in the details later (interface first, implementation later).
#9: Independent components that can be used in different places.
#10: Master your craft.