Regexes are bad, you can often use another way to do it;
While there are many ways to do it, most of them are wrong;
Anyone listing rules for programmers is wrong;
Documentation is for users, comments for developers. You will be a user of your own code, so selfishness compels you to write both;
Tests aren't as necessary as the testing cabal would have you believe;
Tea is the one true source of caffeine;
It's OK to reinvent the wheel sometimes;
There will always be last-minute additions
My second rule is really just a variation on "turn on the fascism options in your compiler; and if the compiler emits warnings that's because your code is broken".
My third rule is a special case of general good practice regarding naming conventions.