This will give you your Maximum Allowable Offer.Another quick method is take ARV*.70-Repair Costs=MAO.Either way you need to know your repair budget.

Based on your experience as property managers/owner operators of SFRs or small to large multifamily rentals, what are the most effective methods you've used to lease a unit? 

I am searching for the best method to finance the purchase of the flip.

I'm looking to do long term rentals except i have no capitol so i've been digging into the brrrr method the last month using the same kinda strategies you mentioned: 100% funding and no seasoning for quick refi and able to pay back the on the fix flip.

More than likely the easiest and most cost effective method  is to install a natural gas boiler and hot water baseboards throughout the building.  

You may have to Sell with many different methods.

The problem that I am having is that when I use the four square method for analyzing rental properties I am getting a cash on cash return of about 6 to 7%.

If the bank uses Fannie Mae guidelines (so they can later resell the loan), it's either six or ten depending on the underwriting method, but I also know that lenders I talked to in Florida were using a more conservative limit of four.

I am interested in using the (BRR) method.

I got started house hacking, local, hands on, learn as you go, everything under my immediate control, expanding at a conservative but steady pace as my knowledge, skills, and capital allowed ... learned risk management actually from my career as a spacecraft systems engineer ... basically, you methodically map out all of the risks (ways things can go wrong) then reverse engineer your investment and financial position in that investment to hedge, mitigate, or all together avoid these risks.