When you're writing code, don't forget that one of the people who might end up using it, one of the people you need to write docs for, is you. Specifically, a version of you 3-5 years from now who has no memory or idea of what you were thinking when you wrote it.
@arielmt 3 - 5 weeks is often sufficient :D
@arielmt Future me? Screw that guy, what's he ever done for me? Don't even get me started on past me, that lazy sonova…
@ersatzmaus best response so far
@arielmt I know time travel doesn't exist because I haven't trekked back here to punch me in the face yet.
@arielmt I’m not a coder, but in my HTML class so many years ago, the instructor taught us to leave hidden notes to ourselves so we knew what the heck we had done, when we had to come back and make edits for the client 3 years later!
@IrimeZane Whether it's mark-up code or program code, that's good & essential advice. 
@arielmt I usually solve that problem by writing the whole thing again.