To bench press properly during chest workouts you need to keep your butt on the bench while performing the exercise. Keep your feet on the floor and you’ll get a small natural arch in your lower back. Pull your shoulders blades inward and downward and contract your upper back muscles to “pop” your pecs out so most of the resistence is targeting more directly on your chest muscles. Lower the bar under control until it touches your chest and try to explode the weight upward for proper bench press form.