Re: how to get thick smoke!
smoke thickness depends on alot of thing. Brands of shisha, rig usig, coals, strength & length of draw.
Many good brands of shisha will produce good smoke, so rarely is that the problem. Often the heat management is key issue - how much (too little) and placement of the coals on the bowl.
Also, smaller hookahs may produce less smoke due to space - less space, less smoke (also hotter and harsher smoke in really small hookah - 15" and less).
Also, if the hookah isn't air-tight, you won't get good smoke.
Alot of things can alter the smoke quaility.
Some good brands that produce excellant smoke: Al Fakher, StarBuzz, Al Waha, Nakhla as well as others.