In case fresh air isn't quite enough, here's a tip that was passed along to me when I had a leather jacket with a problematic odor a few years back. Someone who'd bought a smoky jacket said she'd solved the problem by isolating the jacket in a sealed plastic trash bag for a week or so with open containers of activated charcoal (which can be purchased from shops that sell tropical fish -- it's used in the filtration systems of fish tanks.) Save the charcoal for future uses.
In my case, which was not smoke but mold, this did not work, but I think this was because the odor in my jacket was in or of the leather and not merely on the leather. Should work for smoke if fresh air doesn't do the trick.
