The Outpost Strategy - the simple plan is to locate the various places and ways you can point out your blog across the web. Add your RSS feed to your Facebook profile (and use some of the cool 3rd party apps that let you promote blog posts into the stream- I like Simplaris Blogcast)
The Offering Strategy - provide free resources. Brian Solis builds great offerings all over the place, including ebooks, graphics, and more. Offerings keep people around, if only to add to their arsenal of useful things. See also Chris Pearson and his inexpensive WordPress themes.
The Helpful Strategy - instead of being a consultant and asking “how can I help?” all the time, I like to imagine ways to be helpful, and then build posts that point out some starting point information. This gives me two benefits: it helps me find potential clients, and it grows entire populations of people who linger on my blog waiting for me to write about their vertical again.