Depends. I have been lucky on mine. I look them up on LinkedIn and FB and try to get an understanding of who they are. Family or friends stay? I ask what the occasion is as well (YourPorter App) so I can get a feel for what kind of event it is going to be.
Just make sure to ask enough questions. If you don’t want a party (which Airbnb band all parties right now anyway) be straight forward. I’ve asked people directly, is this a party because if it is we do not allow parties. Just set the expectations and the tire kickers will move along or they’ll book. My rates are high enough anyway that they scare away a lot of the people trying to pool together money to have a party.