this makes sense to me. this doesn't. less fire, less burnt weed. if you're taking hits correctly you don't need to burn excess weed to get a great hit.
Sometimes after I load a bowl, I'll wet the herb with maybe a drop or two or three of water. It seems to burn, last longer I think. especially with especially dry bud Usually smoke out of glass. Hate when people sit there and torch the weed. that only wastes it. I always start and light only a portion of the bowl on the edge of it, and continue in that manner. More people get green (fresh) hits that way. I like to get the bowl cherried when smoking in a group so you don't have to light it every time, so when I take a hit I light it and I cover the top of the bowl with a lighter or hand and inhale, so that there is very little airflow when I am inhaling. In this way the bowl gets cherried quickly and more smoke can be inhaled in this manner. Hope that makes sense....
Less airflow seems like it'd prevent cherrying. Either that or I don't know what an actual cherry is. My friend and I got stoned one day and figured out that since burning is a chemical reaction, burning your weed for too long is just changing more THC into something you can't get high from. We usually light the bowl with the flame to the point where you can see an ember of redhot weed. It's my theory that this redhot portion is practically boiling out the THC in that section like a vaporizer would. We let off gently, and then pass while it's not embered. We start to take a hit, and as oxygen passes, it heats up again. We've killed entire bowls like this lighting it only once. I think our record amount of hits off one cherry is around 39.
In situations where coughing is a problem, I like to take the hit with my waist bent slightly forward. After passing the bong, I sit up straight, increasing the volume of my lungs. Another technique is to not close your throat. Hold the smoke in with your diaphram only.