Re: Thick Smoke
Heat is what really creates thick smoke.You can add more to get more smoke, but you have to be careful because too much will burn the shisha and make it taste harsh. Practice and experimenting is really the only way to start off. Like Sambooka said, try adding a windcover. This can actually add almost as much heat as an extra coal. However, if you leave it on for too long, it might ruin the session. So you have to pay attention to the shisha and sort of "listen" to what it's telling you.
If you feel it getting a little too thick or it starts to tickle the back of your throat, take the windcover off. Then when it's cooled down a bit more and you see the smoke getting a little thinner, put it on again. And so on and so forth. If the windcover doesn't do the trick, then add another small piece of coal. This will largely depend on what size bowl and what tye of shisha you have. So try the windcover idea first and take it from there.