- Identify a number of potential network contacts working for companies that may need the help, reach out to them, tell them about what you're doing and ask to meet for coffee to talk about how you can help them
- Work your network to see who is looking for the kind of service you want to provide - find one client and start small and build on that work
- Find companies you'd like to support and contact the "right" person (maybe the CTO? Maybe CIO? Maybe head of purchasing?") and see if they need what you want to provide or at least give them something to think about for when they need it
- Look for companies putting RFPs on the street for software work (public sites or otherwise though this win rate is probably a lot lower)
- Ask larger businesses in the area and/or consulting companies from more established industries if they are interested in subcontracting for software development
- Ask your current employer if there's any interest in continuing the relationship as contractors for specific applications to give you some runway.
This is by no means a complete list but it's what I would do in order to get it started. Then you'll want to keep doing it all the time and if you get big enough hire a sales / BD person.