Click the fire button 3 times to switch between watts and volts. I prefer watts. Use the arrow buttons to lower the watts to 8. Take a hit or two, then bump it up 1 or 2 watts and repeat. If it gets too warm, tastes funny or starts to taste burnt back the power down.
Be certain and prime the coils before use, couple drops down chimney, fill tank, few UNPOWERED draws, let sit for a few minutes.
When you've found your "sweet spot" use a thumb and hold down BOTH arrow keys at the same time. If the power moves, re set it to the sweet spot and try again. Holding BOTH arrows down at the same time for 3 seconds toggles the "lock" "unlock" keeping from accidental movement/change of the power setting.