I always try to put fliers in an envelope addressed to the specific person I am trying to reach. I also include a short letter thanking the person for considering my company. It will take a little extra work to find out the persons name, but it is good to do research on the businesses you want to work for.
Linkedin can be a good way to find people who work for a business you are targeting. You may also be able to make a connection with the right person, before you send the flier.
Chamber of Commerce events, local civic clubs (Rotary), and networking groups (BNI) are good ways to meet the decision makers for small businesses. A warm referral beats a cold call any day.