I don't allow smoking inside or outside the property at all. I state this clearly in my ad and on the lease, nor do I allow the burning of candles or incense--also mentioned in the lease. Fireplaces are closed off and off limits as well. I state in the lease that damage from smoking can cost thousands of dollars (replacement of flooring, curtains, blinds, re-painting etc.) and that they are on the hook for paying for it if they lie about their habits and smoke inside. Even outside smokers will smoke inside when it gets cold--that's guaranteed.
As for pets, I do allow them. Will allow de-clawed, spayed/neutered, FEMALE indoor cats (males tend to spray urine all over the house) and dogs on a case by case basis. I don't allow certain breeds of dogs forbidden by insurance (pits, rottys, german shepards, etc) and any dog that displays aggressive tendancies--also absolutely no new dogs or puppies as they chew and are not trained to releive themselves outside. Am more likely to allow animals if one of the people on the lease stays home and is there to care for the animal during the day and it they seem to be responsible people. I also collect a $500 deposit for each pet (refundable if there is not damage) and $25-$40 (large dogs) per per additional rent. I state specifically in the lease that the additional rent does not go towards damage caused by pets. Some prefer a non-refundable pet registration fee, but I think having a deposit that they might get back encourages them to be more vigilant about taking care of the property. I state specifically that any animal waste remaining after vacancy will cost them $5 per pile if I have to clean it up.