Word of mouth is huge in the cake biz. Try taking a cake or some cupcakes into Dr offices, real estate offices (these are great because the agents often need food for their open houses), school offices, church offices, and to wedding related businesses.
All of these will come into contact with potential clients.
We are getting ready to move and I plan to hook up local photographers with samples of my goodies and brochures so that they know I am available for smash cakes for 1st birthday photos and such.