Not one method works for everyone. Body position is dynamic. To say you need to look like a certain rider or ideal form isn't an absolute rule. Photos can also be misleading when looking at body position. At the turn in point, the butt is off the seat, the knee is out and your ready to turn. Then you turn in , knee all the way back and then bring it in as needed to just skim above the ground. Your looking through the corner and getting the bike down to the apex. Once your at the apex, your then sighting to your exit point. You're then adjusting your body position as the bike finishes the turn. As your standing the bike up to allow yourself to add throttle, you try to keep your body in the same position. Which means you'll be off the bike more and more as you push the bike up and add throttle. You'll be at the most extreme body position in a photo after the apex of a turn. As the bike finishes the turn, your looking down track,and bringing your body behind the windscreen if your on a long straight. You might leave your butt off the seat but bring your head and chest behind the windscreen if you'll be turning the same direction soon. It's fluid and dynamic. It also changes with pace. The faster you go, the more body positioning you'll use. When tires are cold or if it's raining, I use max body position to keep the bike as upright as possible. Thats how I was taught. But you'll have to try what works best for you, your bike, body composition and comfort level.
Start with getting the butt in the right place. Get your foot positioned well and your knee pull outward and back. This is the first step to work on. Getting your feet and butt in the right places helps you weight the inside peg and reduce lean angle. The upper body can be added later to fine tune. Upper body motions will be relative to your pace, your need to add throttle and fine tuning how and when you'll hit your apex.
Hitting the apex of a corner is essential. But if you turned in early and are pointed the wrong direction at the apex, you'll either run wide or have to wait to add power on the exit as the bike finishes turning.
