Are you charging enough for your space?
Are you charging enough in security deposit?
I have a section in my house rules I call The Penalty Box.
It outlines any charges that will be levied against the security deposit should the listed infractions occur. The wording in the Penalty Box states that should these events/actions occur there is no negotiation, the renter will be charged ( and possibly multiple times per infraction).
My PB list includes $500 for any food or drink found in the hot tub (instituted after a guest accidentally dropped several mugs of hot chocolate in the hot tub and then fought about paying for draining, cleaning, filling and new filters.) $25 for any cigarette butt found on the premesis ( instituted after walking around my yard and picking up over 25). $25 for any dirty dish left in the sink - there is a dishwasher and soap use it daily (instituted when I can into a sink HEAPED with dirty dishes, pots and pans) and last but not least $150 for driving anywhere not gravelled (instituted after the third guest who drove on the front lawn, got stuck, said "i thought we could drive anywhere in the country.")
Spell out the charges up front and make sure you have enough of a security deposit to cover if the charges need to be levied.
I also leave a binder of house rules in the house in a conspicuous place. I thas sections for opening, hot tub use, general rules, THE PENALTY BOX, things to do in the area, emergency procedures, emergency contact info, and closing procedures. I find guests are actually very grateful to have things spelled out and collected in one location.