As a self-employed 1099 individual, your best route is most likely DSCR.

@Nold R.In addition to the great post from Dave, possibly consider an option where the property is taken out of the LLC sooner rather than later and held as tenants-in-common prior to the sale, possibly setting you up in a position to take your share of the proceeds and individually purchase a replacement property via 1031 exchange. 

Separate LLC per Property: Maximizes liability protection but adds complexity and costs with individual tax filings.3.

My best advice would be to read through the contract carefully (builders usually have their own individual contract that's written for them and is leaning heavily in their favor).

and connecting with local REI individuals and attending meetups to learn from experienced investors. 

My contractor has one credit card for all of my individually owned buildings (jointly not multiple cards) and one credit card for the building I own in a partnership.

Break down your rehab into individual jobs, for example get a electrician for electrical work, a plumber to repipe the house, a dry wall guy to close out the walls, etc.

Quote from @Austin Schubert: Quote from @Chris Seveney: Quote from @Austin Schubert: Would anyone have a sample template of a proposal that you've used in the past that goes over how your structure a deal with a private money individual? 

Unless you live in area that has many ADUs already built that have been sold with the home or as individual parcels.

@Jordyn Gegg - I have a PM company that oversees all of my individual LLCs.