Dips

Target Muscles: 
Triceps
Deltoids
Grip: 
Hand-over grip, palms facing down; hands are just outside shoulders
Body Position: 

Hands hold on to each bar and body weight is being elevated off the ground through elbow extension. In this position, keep head straight, push chest out, elbows close to the body, lower the upper body by flexing the elbow until triceps is horizontal to the ground. Slowly return to starting position and repeat.

Positions: 
Hands hold on to each bar.
Lower the upper body by flexing the elbow until triceps is horizontal to ground
Common Errors: 

Elbows away from trunk
The back remains convexly curved – no straight line