Here is what I have so far: Add wash and dryer unitsStainless steel appliancesUpdate light fixturesNew hardware for bathroom (cabinet, sink, shower)New hardware for kitchen (cabinets, sink)Build a fence around ground floor patio Build carportsRUBs programCharge for garbage pick-upAmenities based on demographic (soccer field, BBQ pit, etc.)Adding an extra roomFor other multifamily investors out there, what are some ways you've added value to an apartment to raise rents?

I just did this with my cabinets and put hardware on them.

Consider painting/staining the boxes and getting new doors and hardware (doors can be found at any depot or lower etc).  

I have used Twin City Hardware in the past for Condo fire door replacements.

Not hidden in a sneaky way, just out of sight.http://www.homedepot.com/b/Building-Materials-Builders-Hardware-Jack-Posts/N-5yc1vZc8hw 

I hired a contractor to remodel my kitchen and I left my wallet there.

They chose the latter option and made a copy at the local hardware store for $2. 

Also, if you're in San Francisco, Cole Hardware has a list of handymen, contractors that they hand out in case you need them. 

Most local Hardware stores will have a contact. 

Swapping out cylinders is a breeze if needed and it keeps you from taking apart all the hardware for a lock change out.