Using a Barbell 

Placing your feet shoulder width apart with the bar as close as possible to your body

Keeping a neutral spine position, slightly bend your knees and while placing your weight on your heels 

Using an overhand or alternating grip, push backward using your hips and slowly pull the barbell up squeezing your glutes and hamstrings. 

As you are coming straight up, stop as soon as you are in  (DO NOT HYPER-EXTEND the lower back) normal proper posture

Repeat steps about each complete repetition