I would think about the product(s) that you sell and then think about the products related that you sell and find those websites/ blogs and email them and ask to do a link exchange.

Kind of like this, say you sell couches/ sofas, then think about about all the accessories that people buy when they have bought a couch/ sofa; that would be ottomans, lamps, throw rugs, leather cleaners, etc.., people who are related to what you are selling but not in direct competition. Find those sites/ blogs and offer link exchanges.

My 2 cents. Good luck!