• Get business cards made.
• Pass them out where ever you go.
• Don’t rent a storefront yet.
• Go to people’s businesses/homes and do the repairs there.
• Ask local businesses if you can post a flyer in their window or on their cash wrap.
• Initially, charge a nominal fee…maybe something like $30/hour just to build up a client base and get some referalls.
• Put up a Web site describing your services. It makes you look more legit when you print it on your business cards.
• Hit up local colleges and post flyers there.
• If you’re going to market to college students, learn how to troubleshoot Macs and iPods.
• Develop a protocol for troubleshooting common problems It’ll save you time.
• Underpromise and overdeliver.

Source: http://www.reddit.com/r/IAmA/comments/9usm7/iama_local_tech_repair_man_i_run_my_own_business/

I love the last point. Down talk as opposed to hype and then produce. Even with most services this nearly always guarantees a happy customer.

• "So this is all I could fix in the time I have, all your issues have been dealt with and I also did this..."
• "So this is what I've quickly put together for demo purposes."