Re: When placing foil on your bowl. Do you put it shiny side up, or shiny side down?
I typically place it shiney side down. At first the reason was because I saw a video and read a discussion about the alumimuin itself being bad and the shiny side contining less "addatives", thus the heat would be further away and when heated, wouldn't release bad stuff into the shisha.
Now, I don't think that is a truely valid statement (although it may contain some truth). I place the "shiney side down" becasue I have tested it - the heat management does seem to be easier. Thus, as Dunkel (and others have/will) state, it seems to reflect heat back down into the bowl better. It also does help slightly with "burning" of the shisha - it seems to burn slower and doesn't often burn/boil up thru the holes as often if it is shiney side down.
Also one small minor thing I observed during my testing also tips my hand to the "shiney side down". I notced the coals bounced more on the shiney side than on the matt side - the surface may be smoother and isn't providing the small amount of surface tension that prevents the coal bounce. But... this is a small item. The coals will still bounce on the matt side, but i did notice it more often (and with all my hookahs) than on the matt side up.