I can't take full credit for this idea, as I saw some guys using these electric tea lights with some colored wool. The wool is from Flame of War, XX601 Smoke & Flames. I took the idea a few steps further.
First of all get some of these electric tea lights, they can be found in most places like gift shops and places that sell holiday decorations. I find that you can get them really cheap, just after holidays like Halloween or Christmas as they're closing out these. They're roughly about 30 mm diameter, and are powered by watch batteries with an on/off switch on the bottom. The LED will flicker to simulate candle light.
I first started by wrapping the flame shaped bulb with some masking tape and painting the rest of the body flat black. Next I'll take some cyanoacrylate (aka superglue) and smear a thin coat along the periphery of of the base, using a scrap piece of cardboard.
While the glue is still wet I then took some of the colored wool, shaped it into a thick plume and then wrapped the bottom around the base of the light. Make sure the whole light is cover in wool.
When done, finish shaping the ploom with the light on. These are nice and compact, store easily in a small box, and look great when you set them on a vehicle to indicate it has been disabled or destroyed.