These are some good points. But I still say the best SEO work you can do is an on-page factor: quality content. The idea being that if you have enough, the links will build themselves.

Building good inbounds links is easily the hardest thing to do in terms of SEO. It takes legwork. One trick I've do is join social networking sites and join groups that discuss my niche. I add to the conversation and after a while start asking for links. My best links have come from this practice. I never would have gotten them had I just cold called via email.