One of my fave ways is a 'Waterfall'
You take a Coke bottle, or any other 2L bottle,an burn/cut a hole at the
Very bottom of the bottle

then u get some tinfoil and make a bowl out of it by shaping it and then pokin holes in it wit a needle or watever.

u fill the bottle with water (hold the hole at the bottom) then attach the tinfoil to the bottle opening.

fill tinfoil with stuff...light it and let go of the hole...bottle fills with smoke...then take a hit!

OMG ... ...