learn to make a bong
learn to make a bong

 

 
Extra chambers are simple enough to make. A trip to a hardware shop may be necessary, where you can purchase flexible tubing (ask for non-toxic materials). You'll also need a sealant; Blu-tac adhesive putty is good, but loses it's qualities when it gets wet or old. It's wiser to buy something more reliable.
A single chamber holds the down-pipe. The new chamber is connected to the first by the tubing. The final addition is, of course, the mouth-piece and rush-hole.
learn to make a bong

Extra chambers amount to extra filtration. Filling those chambers with different substances will affect the taste, and texture of the smoke. Plenty of people have different ideas about what works well for them.
Simple examples are filling the extra chamber with crushed-ice to further cool the smoke. Another is; to fill the first chamber with hot water, and the second with cold water. The hot water molecules vibrate faster, hence vapour, and act as a better filter. The smoke is then cooled in the cold water chamber before being inhaled.

Some smokers use an alcoholic drink for their liquid, because alcohol combines well with Delta 9-THC molecules, and drink the liquid after a few sessions. Be aware that, although smoking is illegal (in most countries) before the age of 16, drinking is illegal before the ages of 18 or 21, depending on where in the world you might live.
  
learn to make a bong