Always code as if the guy who ends up maintaining your code will be a violent psychopath who knows where you live.

It should be noted that no ethically-trained software engineer would ever consent to write a DestroyBaghdad procedure. Basic professional ethics would instead require him to write a DestroyCity procedure, to which Baghdad could be given as a parameter.

If debugging is the process of removing software bugs, then programming must be the process of putting them in.

Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it.

Software development is the process of creating a computer software.
It includes preparing a design, coding the program, and fixing the
bugs. The final goal of software development is to translate user
needs to software product, while continuously improving the team
and the process.

Don't include a single line in your code which you could not explain to Anyone in less than a minute.