The barbell row. One of the best exercises you can do in the gym but also probably one of the most butchered exercises you see in a gym. This is due to too much weight being attempted resulting in swinging & bouncing the weight around.

Here is my how to:

Once you have your barbell loaded, stand with your feet shoulder-width apart. Bend your knees and lean forward from the waist. Your knees should be bent, but your back stays straight, with your neck in line with your spine. Grab the bar with your hands (palms facing down), just wider than shoulder-width apart and let it hang with your arms straight.

Brace your core and squeeze your shoulders together to row the weight up until it touches your sternum, then slowly lower it back down again.