You may never collect a dime from them, but you should still take them to court and seek a judgment, then turn that in to a collection agency.

I work with a design agency that handles drawings and permitting throughout the state.

I have invested as a LP in apartment communities where there is a partnership between a government agency and the ownership group to provide affordable housing in exchange for tax abatements and long-term, low-rate government funding. 

(A good rule of thumb is: at least 6 months' worth of expenses for single-income households and 3 months' worth of expenses for dual-income households.) 

(A) For an accessory dwelling unit described in subparagraph (A) of paragraph (1) of subdivision (e), a local agency, special district, or water corporation shall not require the applicant to install a new or separate utility connection directly between the accessory dwelling unit and the utility or impose a related connection fee or capacity charge, unless the accessory dwelling unit was constructed with a new single-family dwelling. home."

@Robert Rixer, I don't know how creative these are, as many are common plays:Valet TrashFencing in first floor yardsProviding washer and dryers for added rentReserved, Covered parkingTech PackagesInternet and Cable contracts, with reimbursementsPayment Plan rents, with small service charge (i.e. bill 1/4 rent each week)Reserved Rental cabanas at poolPrivate pool party rental optionGolf Simulator in clubhouse - fee basedOn site, self serve car wash (quarter feeder style)Charged group fitness/personal training servicesGame room in clubhouse with monthly subscription for tenants (Xbox, Playstation, etc)Changing out high maintenance grass for astro turf or lower maintenance/lower water use shrubberyBut ultimately, I think a lot of NOI increases come from deep dive into understanding EVERY expense and finding ways to minimize them, and/or no outsource them.Train maintenance team on basic HVAC and appliance repairs (find way to get them licensed as needed)Buy paint sprayers for faster, easier turns versus having to hire a contract painter, and possibly repaint whole unit each timeStandardize all finishes, so you can buy in bulk, everything from hinges and door knobs to cabinets, paint colors, and light fixtures.Potentially get leasing people onto lower base salary with higher bonus potentialBulk/bundled insurance across portfolio (even better at scale is to self insure)Regularly test sprinkler systems for leaks.Non-NOI, but benefit to you: partner with insurance agency to get referral kickbacks from your tenant base for renter insurance.  

I own a remote design agency in Florida, but I don't live in the U.S.

I just accepted a job as a marketing coordinator for a local RE agency franchise office, at 21yo, a recent college grad.

The property is ~75% occupied, so it wouldn't qualify for agency programs.The seller is extremely motivated and may even consider seller financing her equity.

Local lenders, agency brokers, credit unions, etc.