Common techniques include:
Increase thermal mass in the smoker. Place a couple of foil wrapped bricks in the smoker.
Use hot water in spent puck bowl.
Use PID to avoid temperature overrun/underun, rather than stock temperature control system.
Note that many forum members find that the stock temperature control system meets their needs very well. However, there are some products that benefit from the 2F +/- control provided by a PID. These items are temperature sensitive products such as cheese, sausage, and fish. Other products, such as pulled pork, ribs, brisket, Canadian Bacon, nuts, salt, etc. seem to do just fine with the stock control system.