I hate sorting compost from guests' garbage.
I hate dumping out partially used salsa/cream cheese/whatever from their containers before I put it garbage. I find it is the most demeaning task of hosting.
I hate guests who say "Yes, I do separate" but they don't.
Mostly I hate that Seattle garbage workers will NOT take the garbage if there is compost in the bin.
As you can see, garbage is very problematic in Seattle. It is expensive to administer.
I have 3 bins in my kitchen - with a pictoral guide of what goes where.
But 2 out of 10 guests are clueless.
The only thing is to make separating as easy as possible, put mandatory separating as a house rule and review guests accordingly.
Wish I knew a better solution.