None of the old cookers I grew up around ever thought of using foil, so I didn't have any idea it was a tool until I found this forum. Until I started using it, my que was always inconsistent and unpredictable. Once I learned about how to use it from the brethren, my product improved immensely and became much more consistently good (would never claim great). I aspire to become one of those great pitmasters who don't have to use it, but I am currently working through what I would term my "foil period" on the way to learning how to do without. (I am from Texas, BTW.) At the moment, I rank it along with Thermapens, remote thermos, and my IQ110 as things I never knew about in my pre-brethren days but I don't want to be without when smoking.
BBQ Apprentice - Old Country Brazos offset, 22.5 WSM, Various gassers, portable grills, etc.