I find many of my clients come from being a member of several area chambers of commerce (networking & referrals), working with creative agencies and from word of mouth referrals 

Digital advertising and consistent content have helped immensely! 

generally speaking I've captured most of the local market by providing a better quality product than my competition. We're very quickly becoming the go-to place for event production, despite being significantly more expensive.

I don't want to sound crazy, but the biggest thing you can do, coming from an event producer, is timely responses and don't out source the work without talking to the planner.

Word of mouth or passing out cards/being seen at other events. 

Direct email marketing: but, not bulk, searching categories, finding appropriate leads, looking at their website, evaluating their content, finding the appropriate contact, sending a curated email. Slow and steady wins the race.