What is the best way to make a connection, develop an "in," and ultimately get work as a freelance book designer/page layout artist with the big publishers, like Bertelsman, Rowman & Littlefield, Harcourt, HarperCollins, etc.?

I have almost 15 years' of such freelance experience, but with smaller publishers and book packagers. I have a website presenting myself and work samples to prospective clients (http://www.tianodesign.com), as well as a blog that allows me to share some of my thoughts on these topics.