Biggest Hosting Duty You Can Do

I just want to point out that the single biggest hosting duty you can do is this:

Have a full or nearly full roll of toilet paper in the bathroom, and at least one more roll where it's easy to find.

Next up is having something to drink, even if it's "just" potable tap water.

Neither of these have been an issue for me lately but it's something I keep in mind when I have people over (although our tap water is good so it's not an issue).