Bathroom Etiuette/Rules

Zeee🚮
Tonight I had dinner at my inlaws for my brothers birthday. I never really noticed that I was the only one who closes the door while I use the bathroom...everyone else is really just has the door wide fucking open like HAAAAY but when I provide privacy for myself, they're just like aren't we family? Then I'm like yeah but it's mine😭
That makes me ask these questions;
Do you close the door/stall when your at someone else's home or in public? What about at your house?
Do you leave pee behind to "save" water? 
What are some things you've done that you see others don't?