Writing is Thinking can apply more generally to the navigation of an idea from inception to realisation. Don't be blocked by starting; get something - anything - down; refine it until it's more signal than noise.
And on writing itself: if you've never coded then writing for an editor is a reasonable approximation to the implement/bug report/fix cycle, with you as the engineer. Do you take criticism as well as you give it? Can you learn from that? What's stopping you?