On the single site level...You are already there with HubPages. Run all of your articles and back links from relevant sites through hubspot or squidoo before it links to your blog or site. Another good method is to run the backlinks through a directory than through hubspot or squidoo before linking back to your site.
The capitalist answer is to hire a reputable internet marketing company to do all the link work for you. Going rate for high quality relevant links is $60.00 to $90.00 for 200 links.