It made me think of a bunch of little shit you should always do when moving in to a new place -
Replace shower head, clean out pipe. Similarly if the sinks are running with bad flow this is often just gunk in the aerator; you can take off the nozzle and clean it out or replace it for $1.
Just replace screens on vents; of course replace any air filters if possible.
Replace the toilet seat. Ours was broken (like everything in this place), but hell it's only $10 for a toilet seat and god knows what diseases the previous resident had, don't bother cleaning it, just buy a new one.
I'm sure there are some other good little things to do that cost almost nothing and take little time and make a big difference. I've replaced most of the light bulbs too just because the previous ones had no concept of good lighting design; eg. a compact flourescent is great for the kitchen but not anywhere else, any bulbs with direct line-of-sight exposure need to be soft white, but bulbs behind shades generally should not be soft white, etc.