In this video Mark Crossfield touches on one aspect of golf that many golfers over look - "the height of your tee". There are many different reasons to use different heights of tees.
For an iron shot you might tee it down so the ball just sits above the ground.
For a 3 wood you could either tee it down low as you would with an iron to hit a stunning low shot, or alternatively you could tee the ball a little higher in the middle of the wood to get a higher trajectory ball flight.
The same goes for the Driver, however there are many different shot type you can do with a Driver. Ian Woosnam was one of the first players to tee the ball up high and then sweep through and slightly down to hit the ball head height. You can also do this by teeing the ball down low like you do with a 3 wood and hitting down steeply on the ball. You can also tee the ball high and hit your driver on the up, this reduces the spin and creates a high launch and long carry.
So as Mark says in the video, you should have a play with different heights for different shots to see what works the best for you.