The grand-daddy and one of the toughest techniques is to position your site for link exchanges.  Link exchanges count how many outside sites with relevant content link back to your site.  

To begin, find out who links to you by doing a Google search with the following phrase: “link: www.yourwebsite.com” (substitute your actual website name in the address).

The concept is that the more outside sites that link to you, and the more related their content is to yours, the better you will rank in the search engines.  To begin building out this strategy, look to your business partners and customers to link their sites to yours.