Look for physical evidence of pot use.

Fourth, add a few decorative touches to make the home more appealing: Place a flower pot full of marigolds or brightly colored welcome mat by the front door; Set a colorful bowl of fruit on the kitchen counter; Install some decorative shelving on bathroom wall; Paint one of the walls in the living or family room an accent color that harmonizes with the rest of the room.Fifth, learn to live with and accept what that renter does with YOUR house.

Also, I wanted to hear their conversations to learn things about why they were looking for a place to rent, do they fight with each other, do they smell like smoke or pot, did they bring friends with them who are people I wouldn't want hanging around on my property, on and on.I know some people think having an open house generates a type of bidding frenzy, but you're still going to have to screen them.  

As well, as get rid of problem tenants without having to evict for breach of contract, and prove that.One type of smoke that you may not be able to anticipate is pot smoke.  

We have annual meetings with housing court clerks and judges that come to our landlord association every year for the past 15+ years, and the advice I am offering is directly from the judges who sit on the bench.

Do they reek of pot? 

The city has a reputation for liberal judges legislating from the bench and free legal offices ready to fight evil landlords.

Some people have different cleanliness standards and if its an issue, then get an old set of pots and pans from Goodwill and people need their own dishes, cups, and utensils. 

We might have some competing pot holes ;)

As everything has to "season," like a good cast iron pot.