I require a $1,000 security deposit, no exceptions and I let them know they will be paying all utilities, mowing the lawn, keeping up the landscaping and cleaning the gutter. 

Definitely check with your CPA, but I am pretty sure you cannot write off the "lost" income but you still get to write off the mortgage interest as well as utilities etc while there.

I work in Albuquerque, NM and wear many hats utilizing many tools.20 rental units12 active flips - recs to purchase -some are now rec notes-private money on the flips utilizing retirement plans/corporate/nonprofit funds-wholesaling and I have started a new platform of providing financed wholesales.would love to see if my knowledge is of value to others.

A little background to start out because I'm feeling a little scatterbrained with the directions to take next: I'm 23 and currently own 2 duplexes with gross income just shy of $4k per month, net after mortgages, taxes, utilities, repairs, etc. is about $2,125 give or take depending on the month.

Learn as some level what the 6 ADU regulations permit.Under utilized zoning: Is there a duplex where there can be a quad. 

With utilities in place city roads   jv deals

What strategies have you found to be most effective in fairly splitting utility costs among tenants?

Are there other loan products similar to the DSCR loans that can also be utilized for investment properties?

No formula can be accurate across the board because even “cookie cutter” properties next store to each other differ as to view, location to the street, topography of the land, lot size, physical condition of the property, past remodeling, quality of the mechanical systems, sunlight, utility bills, past use, etc.  

And the maintenance on all 4, including utilities is much less. ehh, i would have to see the numbers.