A couple of things I've learned about creosote and preventing it.
First, you want to make sure that you have enough air flow. Second, you want to make sure that whatever you are using for fuel (charcoal, lump, etc.) is hot enough to cumbust whatever you add. In other words if you have a tiny little fire don't add a huge log to it. I have even noticed a difference between chips and chunks in my vertical smoker. The chips burn much better and give off the thin blue smoke that you are looking for. Remember, as Dutch once told me "White billowing smoke is evil..." Third, never add cold meat to your smoker. Creosote attaches to cold much like condensation on a cold glass. Let the meat set out at room temp for about a half hour. Make sure your smoker has "settled down" and is emitting a thin blue ribbon of smoke before putting the meat in. I remember the first time I smoked a brisket and thought it was great that I could barely see the smoker for the smoke, the meat was awful, tounge numbing in fact, creosote!!
PM me if you have any questions.