I'd like to know your strategy on burning "clean smoke", or sometimes known as "blue smoke" on the WSM. I usually fire up my 18.5" with Soo's Donut or Minion method and wait for the smoker to get to 250 before putting in any meat. That being said, a lot of the time, when the smoker hits 250, i still get the grey dark smoke. Should I wait longer? provide more air in the bottom vents? Thanks!
I've gone through the same learning curve (and still going through it), but placing wood chunks on the bare grate before adding charcoal solved a lot of my problems with creosote smoke. I do wait for the smoker to reach operating temp before adding meat, and I like to check the grill for yellow stains (a sure sign of creosote smoke) before adding the meat too.
If those stains are present, I take a quick swipe with my finger and taste the residue. If it tastes like a telephone pole smells, I wash the grate and wait a while longer before adding the meat. Granted, by burying the wood, I don't have much creosote problems anymore, but just placing meat on a creosote-stained grill can ruin a cook.
I may get bold and place my wood on top of the heap again one day, lol, but not anytime soon.
My take (and I'm still learning) on bad smoke is that if wood reaches too high a temp, it will produce creosote. I don't know what that temp is, but I assume it is close to the combustion point. The WSM is designed to keep these temps in check, but even so, it takes time to truly master the flame.
By the way, I use the Minion Method, with a single layer of briquettes on the bottom, and a heaping pile of lump on the top. I personally prefer lump (Royal Oak) for greater heat output. Many here use briquettes-only with good success though.