If you're writing, most of the time you can figure out a way to get using the out of the pronoun, whose presence is often dubious to begin with.

"Somebody left their cheese in the fridge" becomes

"Somebody left cheese in the fridge", or "Somebody left some cheese in the fridge", if that meter appeals to you.

If you're talking, it all depends on how much thinking you do before the words come out.