I've worked on a few places that were smoked in heavily. The key to it, as others have said, is the cleaning before you paint. Even aside from the smell, every can of paint in the world tells you that it needs to be applied to a "clean dry" surface. After years of smoking in a house w/o proper ventilation, there can be quite a coat of greasy tar on all surfaces. It's almost like kitchen grease on an oven hood.
I always use diluted Simple Green, (just a pail of soapy water), with a 3M or similar scrub sponge. Works great. I did some rooms a few years back on a house that had been smoked in for 60+ years by the same person. (Plus maybe her parents). The former owner had lived in it from birth to death, she was an only child and inherited the house from parents who died). It was real bad but had also never had anything done inside so it was mostly original paint from the 1920s. The trim was in amazingly good shape other than smoking stains. Oil paint is the best, especially from the old days. Lasts forever in protected conditions.
Here are a few pics, removed wallpaper and did a lot of plaster repair as well as painting. Repainted all trim in oil, it was like doing the first repaint on an original paint 1928 car.
Before:
After:
