Typically I have my painter come in a "touch up walls" like 300 bucks max.

Painters are pretty good about giving estimates.

You need to determine whether these holes can be patched with spackle or if you need a drywall professionall to retexture the entire room (it might be easier to just do this and get it right the first time).A lot of drywall companies work with painters or may even have a paint guy on their staff.

If a painter leaves the rags they stain with in a pile, they can spontaneously combust and cause it to catch fire.

It is hard to justify an expense that would eat up all of a majority of your cash-flow.An investor doesn't necessarily need 'any' professional but it really depends on your knowledge/amount of time you have.For example, technically, most people may not need a painter as the tools are available to them in Home Depot or most stores.

The painter thinks it would not be a good idea to repaint only the lower ones. 

Pulling permits, hiring licensed contractors, being someone anal about the carpenters/cabinet installer/tiler/painters work.  

Quote from @Ryan Painter: New to this platform, long term listener of BiggerPockets podcast.

@Bill B. like Bill mentions we go through the house twice before we close with our sheet rock and painters to make sure its perfect .. 

@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.