Hi there fellow hosts,
I've been reading many horror stories the hosts have been experiencing. Thankfully I have not had any of those issues. I have a few recommendations to hopefully help others prevent from having those problems.
The first thing to mention is to turn off the instant booking. Take the time to kindly ask questions and reply kindly to the guest candidates' questions and only authorize when you are satisfied. When you turn down a guest make sure your answer is polite, truthful and convincing. As a for example, the house I provide has 2 large beds that can accommodate two couples, plus 1 bed for one person. So when a request comes in for 5 people I ask the details and I politely tell the inquirer the bedding is not sufficient for 5 friends who are not couples.
Once they book the house, I make sure I'm there to greet my guests in person before turning the house over to them and leave. If they come during off hours, they use the lockbox to access the keys to get in but I make sure I go to the house the next morning and introduce myself.
I've prepared a house manual that the guests can use to get themselves familiar with the house and the surrounding areas.
I greet my guests with sincere big smiles and warmth and when I see that they came into town without doing their homework, I take them into my car and show the many points of interest around town. Sure it may take an hour or two of my time but it establishes an environment that is kind and warm, breaks the ice and loads the guests with responsibility to act in kind.
This approach got me 5-star reviews from the very first guests I had, till present with no exception and I became a super host quickly and stayed that way.
To summarize, select your guests carefully and establish warm, personal contact. Worked for me so far.
Best wishes and good luck to you all.