Originally Posted by boomhauer
at the beginning it would be harsh either due to burning tobacco or the coals not being fully lit. if your using a QL give it 1-2 minutes after you lit it up for it to get rid of any taste it will have before you put it on your bowl. if its burning by the tobacco sticking to the foil then pack a little bit less ofcourse. the tobacco at the end well all depends on the look. it can be all black and burned or it can be covered in ash or it can be both. breaking your coals into pieces is not always needed but it helps because if there is a little too much heat you can take som off.
Follow Boomhauer's suggestion.. Also, an easy way to know if the coal is ready is that it must be glowing orange all over with a thin layer of ash... Once it's in this condition, you can place it on the bowl and start smoking. If you don't wait until the coals is completely lit, then it will cause a chemical taste at the beginning of the session. Also, it is normal for the shisha to look black after a session, just make sure you don't over pack it like boomhauer said. Another helpful thing to prevent harshness is to use two sheets of foil instead of one. This helps a little bit in keeping the bowl from overheating, but like said earlier, overpacking will cause harshness regardless so be especially careful with that part...
EDIT: Also, you might want to check out the following videos from Sambooka. They are really informative and helpful when it comes to proper set up and fixing harshness.
let us know how it turns out...