On dip bars, bend the elbows and shoulders to lower yourself under control as far down as mobility allows without discomfort. The more vertical you stay, the greater the shoulder range of motion and the more shoulder emphasis; the more forward you lean, the shorter the range of motion and the more chest emphasis. Press back up into full elbow extension.
 
The bars should be approximately a cubit width apart—the distance between your elbow and tip of your middle finger.
 
Purpose
The dip is an effective shoulder and chest exercise and provides a stimulus for both different from typical pressing exercises. It can also help with shoulder extension mobility.
 
Programming
Generally sets of 10-30 reps at bodyweight are appropriate depending on ability; sets of 2-5 with weight can also be used as more of a pure strength exercise.