By using a kettlebell and holding it lower, you decrease the typical spinal stress associated with traditional good mornings while still hitting all the relevant muscles. Do this exercise as a movement prep for big-gun moves like deadlifts or as a finisher on leg or back day to wrap things up with a bow.
Setup: Hold a kettlebell with both hands behind your back, arms straight and shoulders back. Stand with your feet hip-width apart, knees straight but not locked, focus forward.
Move: Bend forward by hinging at the hip, lowering your upper body as far as you can while keeping your spine straight. Rise slowly to the start and repeat right away.