How do you deal with friends who...?

Show up at your door without calling you first? How do you tell them to call before coming over in a nicely way?How do you deal with friends who...?
Just tell them that you'd prefer them to call first because you might be busy and so that it wouldn't leave them feeling left out or them get annoyed with you if you are. If they're a friend they should understand.How do you deal with friends who...?
Tell them you like hanging with them but you want to be sure you will be home when they want to come chill and you dont want to leave them hanging. That will make them think that of course you are being courteous to them, and at the same time you get your privacy again.
if they are ur frends u wudnt mind but tell them u cant handle unexpected visits and u might be busy and u dont want them to feel left out
';well you know chris i would appreciated it if you call before you come over because i might be taking a dump one day and boy i tell you, you dont wanna be here when i do that'; that sounds good rite?
i think you should do the same to them and let them see how disturbing it is.
tell them they can't come in till you clean up a bit... but make sure it's a really cold day, then leave them out there for an hour, and tell them that they should probably call the next time so that they aren't stuck while you clean... haha that just came out of nowhere=)
just b like...';hey umm i would appericate it if u would call me first b4 coming over because i was/is/has to/was going to ___________!';