There’s a difference between what suggestions I would have for another skier now that I know what I know, and what helped me at the time.
To address the OP, what helped me move from intermediate to advanced-ish was helping friends who were struggling at the intermediate level and asked me for some advice. I had to examine what I was doing myself, then try to explain and demonstrate it, and it made me think about what I was trying to do. This was before I became an instructor, actually it helped me to decide to become an instructor, where I actually learned that I had a lot of inefficient habits that needed to change if I was to advance any more.