The backspin seems to be one of the (many?) elements that stumps many skaters. Well, for me it did take a long time to get the hang of it too!
Many years ago, a coach told me that the L shoulder should be in front -> for CCW rotation!! She did also say to look over the L shoulder. At that time, it just seemed too counter-intuitive to be true!
Later, I looked at some pictures of elite skaters, and yes, that is exactly what they do in the air - for multi-rev jumps... Then when I saw the photo of my backspin in Oberstdorf last year (left), well, it wasn't so obvious, but the L shoulder is slightly in front.
Yet another "tip" I heard from someone else was to point the belly button slightly to the right - again counter-intuitive, but the backspin is more than trying to pull the L side around. So, perhaps rather than thinking about the L shoulder, try using the R shoulder to nudge someone standing to the right, and keep rotating about the right side!