Taylor,
My recommendations are similar to Miriam's.
I recommend to people that they join their local Chamber of Commerce, as that provides a great backlink and wonderful local networking opportunities. Plus a nifty logo to add to a website that provides trust in a local community. They can also join the BBB, which gives a regional link. Both of those do cost money, though, and the value to the business depends on the services or products they sell. The BBB fees usually come back within a few months in terms of increased business and clientele. The CoC, I think that is a break-even.
The other option is to find local websites that may not look the best but are local authorities. These would be high schools, community colleges, churches, local clubs, etc. Depending on what they sell, they might be able to get their business mentioned and a local backlink if they offer free services, a raffle, that kind of thing. I.e., a donation of goods and services.
There is also sponsorship of local charity races or other related events such as cancer 5Ks, etc. Youth sports, such as baseball, soccer, football, are other opportunities. As much as I hate to say it, if the person is part of a particular racial minority or "specialty" religious group -- say, a Mormon -- work it! I had to tell one client that from the PNW, who is Morman, and she laughed. She knew what I meant, even though it is cynical to use something like that as a marketing device.
Then there are professional organizations, like the ABA, Interior Design, Event Planning, <insert org="" here="">that they should join, depending on their speciality. Sites like Angie's List and Porch bring some local SEO. Local people do search on those to find local contractors.</insert>
In terms of "free" ways to boost local SEO, Miriam's suggestions re: national directories is also one I make to clients. Granted, Moz and the other directory listings are not free.
If the target market is older, the Yellow Pages (paper) is one avenue.
-- Jewel