Here is a great log to use for your student sign out. It can easily be edited. Room has been left to add your name, room number, and grade. Student writes name, circles where they are going (bathroom, nurse, office, other), writes the time they left, then writes the time they return. This is a great way to make your students accountable for the time they are out of your room. It's also excellent documentation for conferences, issues with behavior in the bathroom and outside of class, etc.