Mostly on trade accounts with local businesses for the materials, some business credit cards, some of the contractors were OK with waiting 30 days for payment. 

My local market only has one power company so I'm wondering how people systemize this...

Quote from @Ryan Daulton: Network with local investors and build relationships.

If you want to network or ask specific questions about your local market, go to your local real estate forum and connect with investors from your area: https://www.biggerpockets.com/forums/86-local-real-estate-networking5.

They also tend to stick with locals to create more affordable housing by locals for locals.

Network Network Network (On the fourms, 1:1 coffee/lunch with local investors, agents, lenders, and in-person at local real estate meetups) - Here is local meetups listed in BP:  https://www.biggerpockets.com/forums/521-real-estate-events-...1. 

Talk to all of the local credit unions.

This is also the best thing, because many out of state investors find it confusing and stay away, which keeps our returns much higher and wards off Wall Street investors from buying up swaths of houses, which we've seen in other markets.As an STR specialist, keeping up with zoning and regulation statewide is a huge part of my job.I also host monthly short term rental events for local investors, monthly webinars, and I also often get furnished, turnkey off-market STR properties.

I belong to a few local Facebook vacation rental groups.  

Carter,Network locally with real estate investment groups and Facebook groups.