Don't smoke onboard, never have.
Do smoke in the hotel room if it is a smoking room.

Most of my flights are less than 10 hours, so even after clearing security if I'm in a non-smoking airport, it will be around 10-12 hours (including boarding, flight and clearing immigration/luggage/customs) before my next cigarette. I get a little grumpy and the first thing I want is a smoke when I can to an outdoor location, but otherwise, it's not that hard for me. Tried a patch once but it left a rash so I gave up that option.