Are you selling a vacant home?
First off, you’ll want to give the local police a heads up that your home is no longer occupied. If you’re running timers on your lights, give them a heads up on that as well, just to make sure they don’t mistake that for someone being in the home. They may not be able to patrol more regularly, but they will at the very least know an empty home exists on your block.
Next, give your neighbors the heads up. They’ll know it’s for sale, assuming there’s a sign in the front yard, and maybe they already know you’ve moved out, but at the very least, you can ask them to keep an extra eye on the home as a courtesy. These are the people spending the most time within eyesight of your place, so consider adding them to your support list.
Your agent will know your home is vacant, but if you have any special requests for them to relay to potential buyers and their agents, now is the time to do it. You can ask agents to keep a light on, for example, or make sure the blinds/curtains are shut at all times. These are common directions left behind from homeowners, so feel free to cater it to whatever makes you most comfortable. Similarly, if you have lights set on timers, instruct agents to not touch the light switches (or you can always put a piece of electric tape over the switch with a note).
Finally, make sure you’ve updated your mailing address and set up a mail forwarding address with the post office. Nothing says “this is house is empty” faster than a mailbox filled to the brim with envelopes and packages, or a pile of those newspaper circulars resting at the base of the driveway.