When I watch top players move around a corner, their crosshairs stay still at head-level, but their body rotates around a corner, kind of like revolving about a corner. Another way to explain is that if they strafe in a direction, their crosshair moves in the opposite direction to maintain watching right next to the corner.

When I try to do this, my crosshairs are pretty shaky and everything feels less smooth, so I would really like to improve at this.

I can try to clarify if my description is not clear enough.