Let's be honest, having boulder shoulders and nice capped deltoids is a nice visual attribute on anyone. They're aesthetically appealing. It's why we marvel at The Rock's physique, and why we do all those lateral raises and shoulder presses with dumbbells.
But you know what's more appealing than just having great looking shoulders? Great moving shoulders. Which is where most people tend to run into issues. Honestly, most individuals walking around during the day have pretty poor shoulder mobility. If you want to see what I mean, take a trip to the airport and watch people going through the TSA scanner with their hands above their heads (this is legendary Strength Coach Mike Boyle's "airport test"). Most people can't get their arms in line over their head, and look relatively uncomfortable doing so.
But we want to build great shoulders, and going overhead can be a really great way to develop the traps and the deltoid. Is there a way that we can work up to those overhead movements safely to get the most out of them? There is, and it takes a series of progressive exercises to get to that point without issue.
To better understand the reason for this progression, we need to understand how the shoulder functions and why a careful progression is necessary.
The shoulder is a ball and socket joint, that has incredible flexibility and is capable of large ranges of motion. This has some setbacks however, as the only place your arm, shoulder, and shoulder blade connect to the skeleton in a bone-to-bone manner is at your sternum (via the sternoclavicular joint). Your shoulder, and your shoulder blade, are then held to the rib cage with an extensive set of soft tissues structures. This makes it capable of its large range of motion, because the shoulder blade can move along the ribcage in a gliding manner (both up/down, forward/back).
The first step in progressing to overhead movements then, is to stop the buck where most people let it go: the ribcage. When we see most individuals go overhead, they ultimately alter the position of their ribcage to get into different overhead positions. You can usually point this out when you see someone in the gym arching their back as they do dumbbell presses, military presses, or sometimes even lateral raises. If we're trying to go overhead safely, we need to address the ribcage first by "tucking it down" and locking it in place with our core. (If you want to test where your shoulder mobility is at, relax your core and raise your arms out in front as high as possible. Then repeat while keeping your ribs pulled down and see the difference).
Once we get the ribcage locked down, we need to develop the posterior side of the shoulder, which helps keep it locked down to the back side of the ribcage. This is to be done with most of your standard movements like barbell or dumbbell rows, and the addition of exercises like the Low Trap Raise that help develop control of the shoulder blade. While you may hear people say that you should keep your "shoulder blades back and down," what you really want is for the shoulder blade to move along a ribcage that is stabilized. In the case of the dumbbell row, that means keeping your ribcage locked in place and letting the shoulder blade fall forward at the bottom and then initiating the movement by pulling it back and down.
After we spend time learning to control and strengthen the shoulder with a locked in ribcage, we can start progressing to overhead movements with what I like to call "almost overhead movements." These are movements that are almost straight overhead, but not completely overhead. These are your Half-Kneeling Landmine Presses and Half-Kneeling Dumbbell Shoulder Presses. These allow you to keep the ribcage locked down, and begin to work through those overhead movements with more freedom of movement at the shoulder blade.
Once we've nailed those movements down, then we start to integrate overhead movements such as Military Presses, Dumbbell Shoulder Presses, and Jerks (if you're an athlete). It also opens us up for better implementation and execution of our other movements like Lateral Raises and Reverse Flyes, which target muscles that stabilize and move the scapula and the head of your humerus (shoulder blades and upper arm to use the layman's terms).
That progression movement starting at the ribcage is what allows us to have healthy shoulders. Now if you're already doing overhead movements and not experiencing pain, but you did the test I mentioned earlier and noticed a big difference, you can always integrate the progression into your training by varying the movements you pick and emphasize how you execute them. If you've not done any overhead movements, going through a progression is key to staying healthy, and building the body you want.