Lots of things, this is such a complex and dynamic topic that no answer is right or wrong. Setting up cleaning operations for 10+ more units is I think of outmost importance, my issue is I've found a cleaner when I had 1-2 units and she was incredible and the way she cleaned my apartments was always top of the line. As operations grew and I acquired more STRs, I still kepts her with the same rate (which is pay per cleaning not hourly), now with 10+ units paying her doesn't make that much financial sense, but at the same time I propably don't have enough work to hire somone hourly, so I'm in a stuck sitaution and don't really know. what to do.
Another problem we have is with the laundry. They intend to strat charging me more for laundry (which was before always included in my cleaning) but now with so many apartments my cleaners want to start charging me for laundry so another area that could be done better from the start.
Then just taking better / more pictures, runnning a social media channel for properties, I wish I also bought cheaper furniture (second hand markets, facebook, offers, etc)
Utilizing more dynamic pricing, making sure that all hig demand dates are priced well
And so on, so on. I could talk about this for hours.