I just use smoke bombs, they work and you can choose the colors you want your trap to smoke, or they have the big smoke bombs that last for like a full minute. If you want to make your own, get salt peter (used in farming? and used buy scientist to grow crystals) mix four parts sugar and 6 parts salt peter and melt it(outside incase it ignites on the stove) in an old pan. it will make a thick paste, pour it into the container you want it in and stick a bunch of matches in it to use as fuses, or reall fuses if you have them, hurry as it hardens quickly, then just light it up and it smokes away. I've never tried it, but I've heard from others that 1 pound of the sugar&saltpeter could fill a city block with thick white smoke. I only put in about the amount that would fit in a shotglass. You can buy salt peter at pharmacies, at least I just have them order it it, and its, best of all, inexpensive! Good Luck