Do You Sew in Your Underwear?

My first sewing book was the Vogue Sewing book circa 1975 and one of the pictures in the section on sewing rooms was of a woman in a housecoat/dress. It's a whole lot easier and faster to fit when I don't have to get undressed every time I try on my garment. I usually sew in my underwear and either a t shirt or my robe, but the robe tend to get caught in the wheels of my chair. In the winter I'll wear tights to keep warm. Obviously, I wear clothes that I'd wear under jackets or coats when I am sewing those. Good underwear is imperative. I tried on my jacket with an old bra (forgetting it was old) and got briefly upset when I saw drag lines from the bust. I actually went and put on a good bra to prove to myself, that yes, I got the bust point in the right place! Being so anal about fit, I try on my garments a lot during the sewing process. It beats getting a surprised when it's finished. What about you? What's your fitting and sewing process like?

I should be posting photos of my jacket, top and pants this weekend. They are finished, but not photographed yet.