I can't understand shooters who look at a target and debate whether to replace their skeet chokes with an IC as if that extra 5 thou of constriction makes the difference between hitting and missing. While they are spinning chokes I'm watching the path of the target, learning what it is doing and deciding where I'm going to break it and where to look so I can. Chokes get thought about last and I only change them if I don't think I have enough for a long, edge on presentation. Usually I shoot light mod and rarely change them.
Here's a video on visualization that I've found very helpful
http://www.youtube.com/watch?v=YLT-LrT-0Fc
I also don't confuse myself with a wide assortment of shells either. Usually I go out with 4 boxes of 1 ounce #8 and 1 box of 1-1/8 ounce 7-1/2 for longer targets.