I'm retired now so just react to word of mouth contacts or just pick up on hints in social contacts. When I was active had Business Cards spread around, a website and flyers around. Social Media (Facebook, etc.) was also useful. I also wrote a series of information articles and offered them to local papers for filler. Had a few published. I live in an area where almost everybody is older than dirt so that's the people most likely to need photos digitized and repaired.