My uncle always teachs me to think for three seconds before I say anything.
During my IT career, I found this rule can apply in software engineering. "Please thinking for three minutes before you write code."
I need to think more before coding. There are many many effects. I need to consider the whole system, not only the parts of my code. Moreover, the cowboy code will effect the maintenance of code base. This is impossible to follow my cowboy code.(note code: my code can be very very hard to read).