I have an 18.5" WSM that I use quite often. A friend of mine also has an 18.5" and recently got one of the 22.5" models. He seems to be having issues keeping the temperatures low in the bigger model.We both use the Minion Method for starting the charcoal but his climbs really fast even with the bottom vents closed.
A good thermometer is a must, it takes all of the guesswork out. I use the Mavrick ET7, which is a dual probe remote.I use one probe for monitoring the meat temp and one for the cooking chamber temp. I actually have two of them. They're available at Amazon.com.
Seasoning is a must. Over the years I've experimented with no seasong or just salt and pepper and found most smoked foods are just too bland without a good rub. I serve sauce on the side. That's the problem with a lot of the big chain type bbq restaurants, they don't use a lot of seasoning. The only commercial rub I use I purchase at
http://www.texasbbqrub.com. There are lots of good ones out there, but after trying several I've really come to prefer theirs.I occassionally use Montreal Steak Seasoning on brisket for a change of pace.
Go easy on the amount of wood you use. Most people tend to oversmoke the food or use green, unseasoned wood which can leave a bitter taste. Some woods go better with certain foods but everyone has different tastes, and a lot depends on what you can find locally. My preference is apple for ribs, oak or hickory for brisket, and cherry or apple for poultry.I received a huge amount of pecan from a neighbor who lost a tree during a windstorm last September. I have just recently started using it after allowing it to season. It has quickly become my favorite for all meats.I did four pork shoulders for a graduation party yesterday with pecan and got rave reviews. I got an order for brisket for a birthday party this weekend, will probably use the pecan as well.
As far as the best, I love em all. My favorite to cook is ribs, favorite to eat is brisket and the easisest and most popular to cook for parties is pulled pork.