The most important step happens before you touch a single sensor: telling your monitoring company the new address so an alarm at the old house is not still dispatching police there after you have moved out.
Pro tip: If you are leaving any hardwired panel or sensors behind for the new occupant, disclose exactly what stays and what you are taking in writing, since alarm equipment ownership is a common source of move-out disputes.
Watch out: Never leave your monitoring service pointed at the old address after moving out; an accidental trigger during someone else's move-in can send police or fire to the wrong house, and you may be liable for a false alarm fee.