Great tip here from Steve at Arizer. Here's what he wrote:
I understand some people like thicker/more concentrated hits, something that can be achieved by 'packing the bowl'. The younger crowd and bong users often like a thicker/more concentrated (and smokey) hit.
That can be easily achieved with the Extreme and V-Tower, it's probably something I should of mentioned before, because the method I'm about to describe is very popular in some circles and extremely popular with those who collect 'pollen' in their (Wicca) Kif Box.
Instead of filling the bowl as you normally would, leave it empty, turn the heat up a few degrees higher than normal, finely grind your herbs, (or use 'pollen powder' from a kif box) and then fill/pack the (dome shaped) screen that sits in the elbow shaped glass piece. You'll be surprised how much you can pack in there, now set the elbow on the bowl as you normally would, let it 'sit and percolate' a few minutes and inhale, that will give you a VERY thick, concentrated, monster size hit . If you're using Pollen from a Wicca Box you're getting a super tasty, super concentrated amount of the finest part of the plant so you can imagine the effect! Blowing balloons with the screen packed is my preference, as the concentrated/thick vapor can be harsh; the balloon helps greatly with that giving the air time to cool.
I tried this out earlier tonight and got rocked! The first hit was super thick, the second was thick, then the third and fourth were about done. I didn't pack the screen all the way full, but left a little concave at the top. Afterward I emptied the cap into the bowl and it looked to be about half of what I normally use in the bowl. This may be the thickest AND most efficiently I've used the Extreme!