I played for 20 years much the way ronscuba describes. Standard Schon shaft (i.e. lots of deflection), parallel english, but I addressed the ball with adjustments already predetermined based on experience and feel. Had I addressed the ball with center ball and then tried to just scoot over a tip or so as spidey said I would have missed anything at distance or with speed.
This year as I started to play again after some time off, I learned CTE, and because of that became more interested in trying to come up with a standardized way, for me at least, to impart english. I thought that would be the nuts - line up super-accurately with CTE, make a little swivel or adjustment, and get position effortlessly. Switching shafts and tips during this process apparently hasn't helped much... But I was getting pretty good at it and need to refocus my efforts.
I setup about a dozen standard shots where english is useful - inside english three railers, spinning out of the corner with inside or outside, spinning up table when off angle to a side pocket, etc. Set it up so I had different distances, different speeds, and different amounts of english. I lined up each shot with center ball, then tried various adjustments to see what if any worked.
Using a Predator Z2, I found that I could actually use pure parallel english for slow to almost medium speed shots of shorter lengths. Once I started shooting harder, or got more than a few feet away from the ball, I needed to use primarily BHE, although on some shots FHE or some combination worked as well. Biggest thing messing me up now is I've been playing with the 314-2, and while I like the more solid hit and have even gotten used to the increased diameter it's amazing how different the adjustments are for certain shots. Still a LD shaft, but a bit more deflection in all but the slowest and shorter shots, and overriding 2 years of feel and adjustments with the Z has been tough.
Also found through this process that trying to mechanize it too much is actually detrimental to my game, it's nice to approximate that way but because of conditions, stroke speeds, etc. you definitely don't want to lose your feel.
I've noticed that the pros use very little english, except when needed, even where I would use say a bit of inside or outside to alter the return path off the rail, they just hit center ball and accept a slightly wider or narrower angle. Hard for me to override 20 years of playing that way, and one of the causes of my current slump and indecision and lack of confidence in my game. Obviously the Filipinos in general use a bit more english and are very successful at it, but for my 4 - 6 hours a week of practice I think focusing on center ball with tweaks here and there will probably pay off in the long run, and I can still keep the fancy english in reserve for when absolutely needed.
Scott