Ok, so I probably had the best session I've ever had last night. I brought my hookah to a friend's house for a party last night, set the rig up around 10:15, and the smoke only started dying out around 12:30. Yes, two hours of constant smoking later, the smoke was just as tasty, cool, and the clouds were just as big as when we first started.
Stuff I did differently this time:
1. Packed it tighter.
2. HD foil pulled tight.
3. Two concentric rings of tiny holes.
4. More careful heat management. I used three coals to get it started, and people were smoking it so often that I had to add a new coal every twenty minutes to half hour or so. I don't have a windcover tall enough to cover the phunnel so I had to go through quite a few more coals. Oh well.
This is pretty indicative of the night:
Thanks for the help guys!