Well Tom, here in the tropical zone of Minnesota (SW) it was a balmy 7.2 F when I just filled my coffee cup. Unlike the "Cat" who lives where the biggest fashion decision made is which floral print shirt or whether to shave his legs today or not, up here we have different layers for each of four seasons, and we use most of them in any given month.
When I shop I try to keep my right hand clear as much as possible, but as a part of my practice I practice dropping packages before "draw." I started this, because when traveling, a daily curse with the new job, unless I want to take three trips out of the hotel I must use both hands.
My ideal is exactly what I saw Ed Head and Masad do this past week - Hand on the gun in a way no one knows. With the "mouse guns," I can have my hand in my pocket, and nobody knows I am in contact with the grip. When I am carrying items in both hands and waiting for something like an elevator or in line I will set the item in my right hand down.
Back to part of your original point, I chose clothes based on carry options and how things could go. I do occasionally find that I am putting on clothes that will make draw more difficult, and then I file it away for the next shopping trip. For those that are concerned about heavy coats in the "cold zone," an extra 500 calories a day for a month and a half will make it possible to wear lighter jackets for easier carry options
