I am a professional cabinet maker and my father is a master plumber.Estimated sale price once complete $500k+Home 2: 210k mortgage. 5 bed, 3 bath redesigned to 5 bed, 4 bath, 3,000 sq ft.

I borrowed $110K from a private lender for the purchase and self funded the repair of the offices. 3 months later, I rented 6,000 sq.ft. of office space to a corporation for $21,000/month + utilities for 5 years with another 5 year option.

Loan Origination Systems (LOS): What works best for mortgage and private lending?

You can save a lot on costs if you do many repairs yourself.Look into hard money lenders or private lenders for the initial purchase and rehab.Connect with wholesalers, agents specializing in investment properties, and other BRRRR investors to find deals and learn more.

Question: Should I collateralize the loan (if using private or hard money), or rely on roll-over loans (to maximize the lower points and 3-4% rate)?

Start small, refine your process, and use your network to connect with local investors and seasoned professionals for guidance.Good luck!

Sounds like I am in the right market for what I am looking for both personally and professionally.

Readers should seek professional advice.

If you want to invest private deals which are generally the best deals then being an agent will kill that deal before it gets going. 

Like @Chris Seveney said, private lending is a great way to go as well.