For foil, it depends on the person, size of it wise. For SWIM
, 8 inches length and about 3 width. Probably 3-1/2. put the product fairly close to one end. Keep the flame at a tip too, because foil conducts heat like crazy. You'll burn the product and/or the foil. Burning the product is obviously a waste, and foil will give a HORRIBLE taste, not to mention burning the foil is bad for your lungs, something about it FUCKS up your lungs. Have a pen that's been taken a part so you just have the shell or the casing (The part you grip). you'll pretty much want it directly over the product, because there's nothing to direct the smoke so it'll go everywhere. Suck HARD. It's pretty much nasty all the time so good luck with that.
To solve the issue of it moving everywhere, create a VERY slight dip for the area of product. The dip is RIDICULOUSLY minimal if you see what SWIM is saying. It's very small. and it's not like a little bump like the size of a pinky, it's like... the size of a quarter, that's what SWIM uses. SWIM sets the foil down on the table and takes the coin and presses the coin down into the foil to make a the dip. The rest of the foil is undisturbed and the dip is present. It sounds like the white residue is from it moving everywhere and the outside area doesn't get liquified and just gets re-crystallized.
RoxasUchiha added 5 Minutes and 42 Seconds later...
Also want that do not keep the flame at one spot like you would a pipe. Keep the tip of the flame a little below the foil and move in a circular motion parallel to that of the dip. Nawmsayin?
Whenever SWIM does this, the product is little or not burnt at all, and the pen casing used as a straw will help with the smoke flying everywhere.
HTH as well! lol Goodluck, yo!