You can do a search on "smoke ring"
Some use a lump or two of charcoal. I wanted a smoke ring when I first started and used the charcoal trick.. I later quit and couldn't discern any difference. I think most agree that a smoke ring adds nothing to the taste of the finished product, but I may be wrong about that.. others will comment. It's just something that happens when you burn a ton f wood in the offsets. My son has a Klose and he likes my Q as well as his.. and he doesn't have to continually buy another cord of oak
I think I get great bark on my product. I just finished a couple of butts and I really had lotsa bark.
I rubbed the butts with French's yellow mustard and sprinked a bit of Tony Chachare's cajun spices on it and then rubbed in some McKormic Steak Seasoning on it. First time I tried this combo and it turned out great.