Personally, I'm currently using IM/IM (in an O/U) for all of my sporting clays. The only exception is on close (like 20 yards and in) rabbit targets. Then, I'll screw in a cylinder. For me, it's just less to think about, and I'd rather always have enough choke.
Now, that's what I've settled on after a lot of experimentation and understanding about my own shooting. For a long time, I shot LM for almost everything, increasing choke (to IM) for long shots and decreasing choke (to CYL) for close shots. For sporting clays, I still think that's best for most people, although if you don't have a LM choke, an IC is a close second.
For trap, I use Full, although from the 16 yard line, anything from MOD on up works well.
For skeet, I use Full, but that's because I only shoot it for fun and practice. If I were shooting for score, I'd be using CYL or SKEET.
BTW, with that chart above... you'd almost think that Briley sells choke tubes or something.