...who leave you the paint cans, for touching-up the paint. Bless them double if they've actually labeled the cans by room.
When we lived in an apartment complex, which was not so blessably managed, the thing to do was wait until they painted another apartment, and then grab one of the paint buckets from the dumpster. They always painted apartments the exact same neutral color, and there is enough paint in an "empty" bucket to cover at least a few square inches.
Having those little dings in the wall spackled and painted makes a huge difference, somehow, in how the room feels.