Ask (or wait for) somebody to honk outside. That's what it will sound like when somebody honks outside.
Knock on the walls to check for insulation. Solid walls will have better sound insulation than hollow ones.
Check the drawers and cabinets for busted latches.
Check out how your phone's reception is throughout the place. Nothing more irritating than renting a place and realizing most of it is a dead zone for whatever reason
Check out the parking situation and see if it's going to be a battle to find a spot if you have to have a car, also worth checking out the area at night on a weekday and weekend to see if you like the vibe then and if parking looks any different with everyone home or friends parking there
Add to that, check for guest parking. Some places are fine for tenants and awful for guests
Speaking of guests, check if they have an overnight guest policy. They usually aren't legal, but it's a huge red flag if they do have one. I remember one of my friends had a landlord that was really nosy about his sex life.
Sometimes kitchens are cramped and things like dishwashers don't actually open all the way, so look out for that.
Look out for who owns the building and who's giving the tour. Is it an owner operator? Live in? Big building? Operated by a management company? Basically you want to figure out how lecherous and shitty they're likely to be.
Also look at what if any utilities you're on the hook for and what appliances use what energy source and what they are. It's just always going to cost different amounts to heat your home with forced central air or cast iron radiators.
If you're in Seattle make sure it has heating or vertical windows do you can install window AC 🙃
Check where all the outlets are and if they all work, and whether they're 3-prong or not.
Run the AC and/or heating and see if you can feel a difference in the room within a few minutes.
Check under sinks and around shower edges for anything that smells off.
