Having flown as a career for over 20 years I have stayed in many hotel rooms and so the experience has taught me a lot about what to look out for in terms of cleanliness.
1. Check the hotel sheets. No one wants to sleep on possible dirty COVID sheets. I can't tell you how many different times I have gone into a hotel room just dying to shower and get into bed and found that the sheets have not been changed. If you do this when you first get into the hotel room, there is plenty of opportunity for the hotel to fix the issue before you are ready to go to bed.
2. Make sure the sheets are visibly dirty before you check out of the hotel and prevent any possible COVID spread. I think it's just a matter of kindness to the next guest and just plain hygienic. Don't feel bad as the hotel should automatically be doing this anyhow. I always wiped the bottom of my shoe across the sheets before I checked out.
3. Place a face towel or hand towel on the bathroom counter to place all your items on. Especially in this time of COVID you do not want to transfer any germs to your face or hands. It's also a visual reminder of anything placed on the counter and it helps in not forgetting items like jewelry in the bathroom.
4. Take an extra washcloth and wipe the toilet seats down. I think we all assume that the hotel room has been cleaned thoroughly but my experience has shown that the toilet seat is often overlooked.
5. Treat hotel room floors like airplane bathrooms and never assume it's just water. I can't tell you how many times I've passed through hotel corridors and seen the remains of a hotel room party gone wild. Let's face it, the hotel does not have the manpower or capability to thoroughly clean hotel room floors, nor do they often have time between checkouts. COVID can be easily spread through bodily fluids.
I hope my tips have been helpful, check back in for more of my lived travel experience.