Not sure what steps i might have skipped or misinterpreted, besides the river. you're right though, I find myself working with opacity/flow options more with the tablet in the last month or two than I ever have before. It's likely that a few of my typical habits made themselves known while I was working on a few things. That having been said - I learned a few new techniques to add to my methods, and in that respect your tutorial is 100% effective as a starting point for new ideas
(and even if it won't let me rep you yet, I did get to rate the thread at least!)