I will go with "word of mouth". It worked for me and others I have worked for.
I have some simple steps that may help you.
1) Hire only the best. Clean cut, drug free and the ability to find other paying jobs on the same site. You get what you pay for.
2) Make sure your service truck is clean inside and out. Well stocked. Your employee is clean and well mannered. First impressions are very important
3) Have business cards. To pass out when you meet with potential customers. Always have a few in your pocket or wallet.
4) Advertize in the newspaper.
3) Advertize in the Yellow Pages. If you don't have a company name, pick a name that will be the first listed in the directory if possible. Like "Abel Electric" The sky is unlimited in a name.
4) Always follow up with customers AFTER a job and make sure they are completely satisfied.
5) If you tell someone you will call, check on something ect...make sure you do.
6) Others here may have many more suggestions. Read them and decide what is best for your company.
Note: During your interview proccess, while the prospective employee is with you, have someone go out and look inside their car or truck. If it is filthy and piles of McDonalds bags are piled up on the floor. Think of what he or she would do on the job. Would he clean up after himself? Would he leave hand prints all over the customers walls? And on and on.
I know this sounds a little over board, but we tried it at a big company I worked for and we found that if the car or truck test passed, we were happy with each of those hires. They made us proud.