Set the appropriate weight taking account of your fitness level and training type. Sit on the bench and grab the barbell a little wider than shoulder width. Lift the barbell from the rack above your head and hold.
From the starting position lower the barbell in front of your face by bending your elbows.Go down to your neck level. From that position return to the starting position the same way. Inhale while you are in the lower (starting) position and exhale going upwards.
Choose the appropriateweight taking account of your abilities, overall fitness level and training type. Start with lighter weight to master the technique well. Return to the starting position with a slow, controlled motion rather than quickly relaxing the tension in your muscles. Avoid involving the trapezius muscles. Fix your torso while doing the lifting to avoid bending at your lower back.
It is better to exercise with assistance of a spotter or trainer when using heavier weights.