Things like wrong brick or brick color. 

So is the brightly colored over the top places.

Shingle manufacturers change their colors every 5-8yrs, so you should be able to find the same matching shingle and blend it into the existing. 

The kitchen cabinets were three different colors, so I knew unifying them would help visually.

Specifying colors, tile, cabinets or anything else in a rehab is directing the borrower.

@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.  

Only put in popular, neutral and unobtrusive fixtures and colors.

Mix FOOD color with tap waterb.

Grays, white and blues for colors.

Quote from @Susan Maneck: You disparage a group based upon there ethnicity or color of there skin.