There is some fine advice on this node, but I felt that I should add some more. What is described above I have normally referred to as simply a 'bucket'. It is, however, perfectly possible to construct a bucket bong.
You will need a bong head and
a short length of tubing, and the same equipment as above.Start as outlined above, but create a hole in the bottle lid large enough to feed the tubing through. The tubing should reach down no further than the point at which you cut the bottom off at. Push the bottle as far down in the water as it will go, and screw the bottle cap back on Attach the head to the tube, fill with grass or solids, preferably a nice mixture of both and pull the bottle up while applying your flame of choice.
It will be a little difficult to pull to start with but once the critical point has been achieved, air will begin to be pulled over the head and through the tube, bubbling up and filling the bottle with lovely cooled smoke
Have two in a row, you deserve it, after all the engineering work....