In my house, we have pillow fights. Instead of everyone having the same cases, it's like a game of checkers.
I have the light colored cases, and my hubby has the dark colored cases.
Sometimes he ends up with mine. Sometimes I end up with his.
Every once in a while, I change out the cases, being careful to replace with the same color it had on it. It's less confusing that way.
We have a drawer that exactly fits under the bed with clean cases and sheets.
I spray the pillows with a Lysol spray to kill any bacteria. At some point I will just wash the entire pillow, or buy new. This is probably why we have so many right now.
There's something about a favorite, well worn and firmed pillow.