Odor from cigarettes tends to linger a lot longer than the smoke itself. Leather furniture absorbs cigarette smoke and holds it in so long that a secondhand piece may smell like an ashtray long after it leaves a smoker's home. Fresh air and natural odor removers wipe out those smoky scents, but it may take some time before the smell dissipates completely.
Carry the furniture to a protected outdoor area such as a garage or screened-in porch, if possible. If you can't, remove any removable cushions and take those to a protected outdoor area. Air the furniture or cushions out for several hours to several days during dry, non-humid weather. If it's not possible to take the furniture outside, skip this step.
Carry the furniture back indoors, if it is outside. Sprinkle baking soda liberally over all surfaces. Remove cushions and pillows, sprinkling baking soda on each, as well as the seat area where cushions belong. Leave it on for an hour or two.
Vacuum the baking soda up using an upholstery-brush attachment. Flip over removable cushions and pillows after vacuuming, and sprinkle baking soda on the exposed sides, vacuuming it up after an hour or two.
Mix equal parts white vinegar and lukewarm water in a bowl. Dip a soft white cloth into the mixture, wringing out excess moisture. Wipe all the leather areas down with the damp cloth, including all sides of each cushion and pillow. If the furniture is suede, brush the suede gently with a nylon-bristled brush after applying the vinegar solution to help work it into the fibers. Allow the furniture to air-dry completely. Use a ceiling fan or portable fan to help dry suede, which may take a little longer than smooth leather upholstery.