This may seem like a simple enough task, teeing the ball up that is. You may think that you just walk onto the tee box anywhere, push the tee into the ground until it is at the desired height, and then go about hitting the shot. However, the importance of this simple act is grossly under estimated.
First off, tee height is very important as it will have a great influence on how you contact the golf ball. Obviously teeing up a driver is much different than an iron but tee height can vary based on the scenario even with the same club. For example, many golfers will tee the ball up too high with an iron which will definitely not be effective into the wind as there will most likely be a loss of distance. On the contrary, if you feel that a little more margin for error on your contact will help then teeing the ball where you can see the top of the tee when standing 10 feet behind the ball may make sense.
The other aspect of teeing up the golf ball which will impact how you execute golf shots is where you tee the ball up on the tee box. The basic idea is for right handed golfers to tee up on the right side of the tee box to hit a fade and visa versa, however, there is more to the story. Paying attention to where the tee box is aligned is essential so that you are not subconsciously lured into aiming incorrectly. The idea is to setup on the tee box in a way that you feel you are hitting away from the side with trouble or so that you are aligned to shape the ball with the hole.
This is something to pay attention to not only on the golf course but in practice so that you can build the confidence in how you are approaching different scenarios.