I highly suggest you start reading George Morris and his critique columns in the Practicle Horseman Magazine, and look into his books.
There is alot involved.
ETA: I agree with you Upnover.... there are awful examples in all disciplines. Most of the eventers I've seen in the jumper classes at the regional shows make me cringe, more so then most hunter rounds. But then again everything at the lower levels is compounded and bad usually.