This is not an exhaustive list but kind of works for me
1) Be part of the community here, ask questions and answer them. Follow users and leave fan mail. Comment on their hubs and if you find something relevant to your hubs then why not post a link (use the comment section to ask permission, not forgetting to leave a link to the hub that you want to connect their hub with). For example, you find a hub about pull up bars, go to the comment section and write something like "Hi, would you mind if I link this hub to my bebrown.hubpages.com/_load/hub/Which-Chin-up-Pull-up-bar-to-choose hub?"
2) Facebook, twitter, shetoldme and similar sites - build up a presence on there and make sure your URL is in your profile. Don't rush off and create an account and say "hey look at my latest hub!"... you will be ignored as a spammer. Rather try to contribute and be part of those communities and build up a trust.
Of course there is the SEO stuff as well but the above 2 work well in the long run too.