This is all great advice and methods that I subscribe to using. Luckily for me, I took advice from some good fisherman when I was learning a few years ago and it really helped me speed up the learning curve. If you want to catch trout consistently on the clinch takes notes from the above post pertaining to indicator fishing. Like Rod, wolf, and many others I also choose Lefty's yarn over any other. That stuff is worth every penny.
As for the sulfurs. They are tricky and has Travis mentioned, sometimes a slight change in your fly can make all the difference. There have been times where I've felt the fish will eat just about any resemblance of a sulfur and times where I've thrown every thing at them and got nothing. That is why we fish I suppose.