Hey Scott
I haven't reached "Big Boy" status, and probably never will. But in the years that I've been riding, it's been a constant progression of small steps with a few breakthrough moments added in.
The first breakthrough came when I bought proper gear and took a few lessons. I cleaned up my technique and made huge progress in just a few days. No surprise there. The second breakthrough came the year I attended SES. No one taught me anything specific, but riding with all of those great snowboarders radically changed my perspective. They inspired me and made me realize that I could push so much harder than I had been. And I did.
A few years ago I caught my toe edge and was catapulted into a Pete Rose type slide. When I landed, I dislocated the shoulder of my trailing arm. For the next couple of seasons, I was very timid when transitioning from heel to toe. I couldn't commit to the toe edge when it was the downhill edge for fear of catching it again. I was in a defensive mode. In a clinic sometime after that, the instructor mentioned how you should build the turn from the board up, using your ankles, knees, then hips. I already knew this logically, but up to that point I could not get myself to actually do it. But that day I was ready to believe it and everything changed. I could feel the edge locking into the carve *before* the weight of my head and torso had crossed over. That created a seamless transition from heel to toe and gave me full confidence to dive into the turn. It was perhaps the single biggest breakthrough I've experienced in snowboarding. It is a subtle thing, but had a tremendous effect on my riding.
John