Put the brisket on ice cold and wet. Don't dry it off before putting the rub on. Also, consider throwing it on before the smoker comes up to temp. My stick burner produces a much larger smoke ring than my WSM, even though the meats are prepared identically. So the cooker plays a big factor too.
I agree with Curt that the smoke ring probably doesn't matter, but it looks good and certainly doesn't hurt.
The Pickled Pig
Twitter - @ThePickledPig
CBJ, WSM, UDS Cookers, Weber Gasser, Weber One Touch Gold Kettle,