I've been reading a few articles about moguls, including this one which suggests the key is pre-jumping.
A major key is a pre-jump, which is supposedly an alpine racing technique but we all use it. It’s what you do when you jump a cliff or come over a knoll. Think of the crest of a mogul as a chain-link fence. You walk up to it, squat down, explode up as hard as you can, throw your hips through and up, and at the apex of the jump, you suck your feet up. That’s how you jump anything. Don’t let the mogul push your feet: Actively suck them up. Jump before you get to the crest of a mogul, pull your feet up and over, land softly and high on the backside then skid to dump speed.
However, when I watch videos of good mogul skiers like Jonny Moseley, that doesn't look like what they're doing. They look more like they are passively allowing their legs to rise with the mogul (which fits with the pre-jump idea), but I don't see any evidence of working the backside. So if I had to guess I would say they are about 80% prejumping, and 20% slowing down against the front of the mogul.
Anyways, I'm interested in any clarification people are able to provide.