Just like the reality, Smoke also exist in the game Little Alchemy 2. With Smoke you could combine Acid Rain, Chimney, Ham, Smog, Smoke Signal, and Tobacco. There are at least 9 ways to make Smoke, but the simplest way is to use Fire and Air, other methods are of course too more complicated.
So we suggest you give up other methods, you do not need to waste time on those complicated process with too much steps. Just the simplest method is okay.
Fire + Air = Smoke