One of the main things I always have to address at roping schools, clinics and lessons is the importance of staying balanced and having correct posture. Having your shoulders set right, and your body and head upright with your eyes level is important. Roping is somewhat of an athletic sport, so your body needs to be in the right place. Good posture helps you ride your horse, swing your rope correctly, and see and judge whats happening in the run, so posture is an important part of the process
When you're coming down the arena, you should be sitting upright and keeping your body straight up and down, and centered in the middle of your horse. Your left shoulder should be a little bit forward and your right shoulder should be back a little. If you pick your horse up and have your horse in your hand, bringing your left shoulder forward helps pick your inside (left) rein up and lets you arc your horse to the left. It brings your left foot into your horse a little bit, which also helps form that left arc.
Having your right shoulder back allows you to swing your rope down over the left side of your horse and keep your hand back behind your head in your swing. It structurally forms you in the correct position to pick your horse up right, have the plane of your swing correct, be ready to make your corner and square up on the steer, and have your swing down over the steer's back.
As you develop your roping ability, your horse tends to want to protect himself because you catch a lot more steers and he gets a lot more jerks. Keeping your body in one spot through the whole run won't cue him and tell him you're getting ready to deliver your loop, which keeps your horse from anticipating your shot and getting short.
A lot of amateur or low-numbered ropers have a bad habit of changing their body position in their delivery, which cues their horses to stop. Their horses tend to get quick or short. Leaning down also keeps those ropers from getting a good loop delivered.
For the most part your top-level ropers have good posture and really sit upright on their horses with very good form. There are a couple of guys I know who've been great ropers for a long time who tend to lean forward a little more than others, and they even teach their students to go ahead and lean forward a little bit. What they do really well is not change their body position in their delivery, so their horses don't get the cue to stop. It's not my way, but they've figured out a way to make it work for them.
When I was a kid, I watched the great ropers and tried to learn from them. The guy I tried to emulate more in my riding style than anyone was Leo Camarillo. He had such good up-and-down posture, so that's what I worked to develop. Any time I found myself leaning off to the right or leaning forward, that was a cue to my horse. I knew it was a bad habit to get into, so I always worked to have good athletic posture. Staying in the middle of my horse is what worked for me.