There is a lot of misinformation online about how to setup the controller (point the antennas) for maximum range.
Below is a diagram showing the most effective method to achieve maximum range using the stock antenna system. As you will see in the diagram below the strongest signal is radiated off the side of the antenna. The end of the 5.8ghz antenna is actually very weak.
When you fly you can visualize an imaginary line from your controller to the aircraft. Keep in mind when you first take off and as you start to move away your controller will need to be tipped a little more vertical than normal and as the Phantom increases its distance from you your controller will become more horizontal.
The 2.4ghz WIFI extender has maximum gain off the front of the unit as show below.