For smoke from the audience I frequently use an anti-histamine tablet ( only drug that I'll use !!). I'd prefer to use a fire hose on the smokers though !!.
As for psychological prep - in the group we talk for 10 minutes before we go on about the good performances we've had and the one that we are about to deliver, remind ourselves that the audience is there to have a good time with us rather than be critical.
The other thing that helps me is if I speak to some og the audience before we get on stage. I've then got some "pals" in the hall.