Known for being one of the most devious scoundrels of the sixties, rebel activist Abbie Hoffman went down in history (among other things) for his publication Steal This Book, a guide to living for free- "a manual of survival in the prison that is Amerika". Boing Boing has excerpted Hoffman's recipe for the perfect smoke bomb from the book, along with annotations on the process.
"Sometimes it becomes strategically correct to confuse the opposition and provide a smoke screen to aid an escape. A real home-made stroke bomb can be made by combining four parts sugar to six parts saltpeter (available at all chemical supply stores). This mixture must then be heated over a very low flame. It will blend into a plastic substance. When this starts to gel, remove from the heat and allow the plastic to cool. Embed a few wooden match heads into the mass while it's still pliable and attach a fuse.
The smoke bomb itself is a non-explosive and non-flame-producing, so no extreme safety requirements are needed. About a pound of the plastic will produce thick enough smoke to fill a city block. Just make sure you know which way the wind is blowing. Weathermen-women!"
Click through for Boing Boing's notes.
OR if you prefer video (or make a colored smoke bomb like the grenade pictured above), peruse the selection of smoke bomb tutorials below.