Good mornings are a great way to build a strong posterior chain – all the musculature in the back of your body. These exercises strengthen your back so that it's strong enough to take the load. Do them right and your squat and deadlift numbers will grow.

1. Standard Good Mornings: Basic good mornings are a great way for you to do a loaded hip-hinge pattern. It's the first step before you learn other variations that'll create brutal back strength. It requires you to engage your entire hamstrings, glutes, and lower to upper back.
2. Dead-Stop Good Mornings: With this variation you have to create tension in the hamstrings prior to starting the movement. Due to this exercise being concentric based, you're less likely to become extremely sore.
3. Good Morning to Squat: This is a great max effort exercise and an even better accessory movement. Perform an eccentric (lowering) good morning with a concentric (lifting) squat. The benefit? It'll hit both your posterior and anterior chain.
4. Seated Good Mornings: This is the most advanced variation. Brace before attempting this movement. When done correctly it'll help you build a bulletproof lower back.

All of these can be performed with a specialty bar. The safety squat bar or the cambered bar would be the best since they sit comfortably on your back and won't roll forward on your neck when you bend over.