I posted this in another thread, and thought I would share it again here for the benefit of new smokers...
I tried every packing method imaginable, but nothing ever worked. Then everything fell perfectly into place when I started properly drying and gravity filling. It's also important to have a properly drilled pipe (hole not too high). ::Wet, bitter-tasting tobacco at the bottom of the bowl is a clear indication of your tobacco being too moist and/or being packed too tightly. I had these same problems for a long time until I finally figured it out. I now smoke every bowl down to a fine gray ash with no bitterness or burn.. this includes aromatics. The key is to properly dry your tobacco before smoking, and gravity fill it. Don't pack it. Let me repeat that again- only gravity fill it. The tobacco needs enough air flow to burn properly. And when tamping ash, only use the weight of the tamper. It really is as simple as this. It stays lit better, no more tongue burns, cool and flavorful smoke, bowl dry at the bottom after smoking, and no more wasted tobacco.