Here is one that most people miss. There is a ton of information about loading up the pit with hickory, mesquite or oak. One of the best measures of offering flavor "through the air around the meat" is via cooked veggies. For instance, take an onion and chop it coarsely. Next, coat it lightly with olive oil. Then wrap it in heavy duty aluminum foil. Finally place it by/near/on the fire to make the onions begin to cook slowly. In just a few minutes, the exhaust from the pit will be heavenly. You can only imagine how wonderful the meat will taste.
Just before they are all burned up, remove them and go to snacking. Experiment and season them before you place them in the pit. They need to be down by the fire where they can cook and release their aroma.
Try the same with garlic, bell peppers or anything else you might think of. Experiment and mix an match. Once the first packet has been completed, have another one ready to go!