Good tips in here. I've found that other than not knowing how, the next biggest reason people don't write good code is that they consider doing so to be too costly. It's simple to justify that viewpoint if you just define all code other than the way the programmer feels like writing it as prohibitively difficult. Everything becomes an insignificant nit or "not worth doing right now" and the result is a death by 1000 cuts. It's easy to use these ideas as a shield against being diligent and paying attention to detail.
Some good basic tips, but...
The most difficult problems in relationships are having to repeat the story of how you met??