Grab a hold of the chin up bar in a wide grip and cross your legs at your ankles. Hang down for a second or two as you get ready for the initial pull up. This is your starting position.
Pull yourself up until your chin is above the bar. Then, lower yourself back down again but don't fully extend your arms; you should always keep tension in your arms for optimum movement efficiency.
Finally, repeat the entire movement for the desired or prescribed number of repetitions.
DO
DON'T
Perform this exercise in a smooth and fluid motion
As you get tired, try to perform partial repetitions (get yourself as far up as you can)
Don't extended your arms completely on the downward portion of the movement
SPECIAL NOTES & LEVEL of DIFFICULTY VARIATIONS
To increase the level of difficulty, slow down the movement or use a dip belt and put a weight plate between your legs or use heavy chains placed around your neck.