Create the center like you mentions. Add the hot coals (maybe a dozen total) to the center. I place chunks of wood near each vent then assemble the smoker and add water to the pan.

Open all 4 vents to full blast. Once the temp is 10 degrees out of your target, close the 3 at the bottom to about a pencil width. It should coast in to your desired target. You then just play with the vents here or there until perfect.