You need a diverse portfolio of links. Off the top of my head I would do this:
1 - In content links. Private blog networks, guest blogs, web 2.0's etc. You can also use these for your tier one links and build links to them using the rest of the steps below.
2 - Social mentions. This includes social news sites like digg, reddit, stumbleupon and then hit Twitter, Facebook, LinkedIn, Pinterest etc.
3 - Social bookmarks. There are many ways to get these just pick one and get a lot of them.
4 - High PR Links. You'll need to get some powerful links to make your rankings stick/move up from when you get stuck. I would not recommend you use a private blog network service offering high PR links unless they stick on the page with PR. These need to be permanent high pr links.
5 - Low quality links in mass. You may not want to hit your main site with these types of links if you use software, but if you do them manually they are just fine. Blog comments, Forum signatures/profiles, wiki's etc. You can use these to build links to your already built links as well to make all your links stronger.
6 - Make sure all your links are crawled/indexed using lindexed/linklicious type services etc.
7 - Repeat as necessary. If you do all these steps, you'll get movement, it's just a matter of how far you can go depending on how many and how the quality of links you get.
8 - Don't forget to add content/update the site. This is very important. And don't send all links to the page you want to rank. Spread links throughout your site. All links pointing to the home page isn't natural. I've found that linking deep into a site will make all pages rank higher as long as your internal linking structure is sound.