Set the TERMS as non refundable within a certain number of days before booking. If they show up, you get paid. If they don't show up you get paid. If you're cash basis then tough luck. Look on the bright side. Offer a last minute deal to someone else or take some time off.
Get an electronic door lock so they can Self-Check In.
Give them a code
Change the code for each guest.
I like this Schlage see photo
If you love what you do, you've maximized your happiness. The rest takes care of itself.
I don't. If they want to hear from me I'm sure I'll hear from them :)