- Take the cap off a squash bottle
- Pierce one side with a divider from a geometry set to act as a handle
- Pour a bit of cooking oil into the cap
- Hold it for several minutes over a candle flame
- Soon, the whole thing will catch fire
- Place it on the ground, and sprinkle some water on the burning cap/oil

You'll see flames shoot up, like in those mantravati movies where they throw bhasmam into a fire and flames rise up to the ceiling. Only sprinkle some water with your fingers, don't pour too much water, because then the fire will go out. Its best if you do it in the dark. Its fun!

Disclaimer:
Please be very careful when you do this. If you damage property or health or lives, its your own responsibility.