Mastering is a completely, completely different animal, and I’m not sure how much I have to contribute to a general discussion of mastering other than to say don’t master your own mixes. If they don’t sound right, fix the mix. There is nothing that a home recordist can do in the way of self-mastering that they can’t do better by re-mixing.
The point of “mastering” (in the sense that most recording forum-goers think of it) is to fix the stuff that’s wrong with the mix. Which, if you can hear it in your own mix, should be fixed in the mix. That way the mastering engineer (even if it’s you) doesn’t have to worry about anything other than duplication. What nerd-factormax is doing is not actually “mastering.” It is “making a two-track mix sound better.” Which is something that mastering engineers frequently do, because they often get flawed mixes that they can improve, but that process is a sort of “pre- mastering” (in fact, pre-mastering is exactly what it is called).