Pick a theme for your room that is neutral and impersonal to accommodate all sorts of guests. For example, a Disney theme would work well for your children’s sleepover, but not so well for your in laws.
Colors like warm beiges and browns, or cool whites and blue hues like seen here work great in this type of setting. The most common mistake many home owners do is decorating their guest bedroom with leftovers from other rooms. Keep it from looking junky and attempt to remain some consistency with matching furniture.
Tip: Keep a bench at the end of you bed like the one seen here to easily stash away shoes.