Definitely scour the profile for the giveaways like PNP, Party, and T. A guy who is now advertising as NicoStylesXXX in NYC was my worst experience in this regard. Was glad to get him out of the house without an incident, and after I posted about the experience here he let me know that he was not happy with me 😬 After that experience I have taken to asking providers, before confirming the appointment, if they party. If one says yes, I politely tell them "thanks but no thanks."
I have also noticed some guys who seem very dependent on poppers. I don't use poppers myself, but it seems to me that some guys seem to have developed an over-reliance on them in order to perform, and this seems to lead to performance problems.