Good luck convincing anyone of that, Rusty!
Breakable crust is one of the truly challenging conditions in skiing. But as I always say, there are only two kinds of snow conditions: conditions that are good...and conditions that are good for you! Breakable crust can be really, really good
The thing about breakable crust is that it, perhaps more than any other condition, demands OFFENSIVE skiing movements. That is, speed control coming from the line you ski, rather than from the braking effect of skidding skis. But breakable crust is intimidating! So offensive movements are counter-intuitive. Even highly skilled skiers become defensive in it. And defensive movements do not work in breakable crust. Hit the brakes, crash--it's a pretty consistent pattern! (Of course, to get a good taste of ANY conditions, you've got to eat some....)
As Rusty says, you do NOT want your skis going sideways in the stuff. No skidding. Nothing will catch an edge and trip you like breakable crust. You CAN'T catch an edge if your skis aren't skidding--so keep 'em pointed the direction you're going. Or go the direction they're pointed. Either one works.
That leaves you with two options. Either hop your skis completely out of the snow, redirect them in the air, and then set the edges cleanly when they return to the snow, or keep them firmly in the snow, "carving" turns with smooth, progressive, highly skilled tipping and pressure control movements. Both of these strategies have their advantages and their limitations.
You really can't control (i.e. twist, skid, or displace) your skis when they're locked in the snow, so the theory behind the first strategy is to spend as little time as possible there. "Float and sting." Set the edges, then rebound or hop as quickly as possible back out of the snow. It's an effective technique, but it takes a lot of effort and athleticism. It's aerobic and exhausting. And you can never quite tell what's going to happen when those skis hit the snow--that's the nature of breakable crust. Sometimes they break through, sometimes they don't. So timing the movements and keeping a smooth rhythm are a challenge. You're likely to get tossed out of balance with each edge set and rebound. On the other hand, you can easily move your feet beneath you in the air to make the needed recovery.
A couple more thoughts on the "float and sting" technique. Make sure to use BOTH skis at once ("simultaneous leg movements"). Pressure both skis, and hop both skis together off the snow. If you try to stand on one while turning ("stemming") the other, that platform you're standing on will let you down, with embarrassing, if not painful, results! Try to maintain a rhythm. Your skis will behave like springboards. When they want to spring you back up, GO with it! If you hesitate for even a microsecond, you will lose the energy stored in those bowed skis, and you will have to work MUCH harder. With this thought in mind, land softly, flexing your legs to absorb the impact, enabling you to sense the buildup of pressure and to spring back at just the right moment. No traverses! Because of the inconsistency of breakable crust, each turn may have a different timing--sometimes the skis will immediately load up and snap back quickly, other times they may bog down and delay the effect. Pay attention to what your skis tell you, and work in harmony with them.
The second strategy is far more technically demanding, but much smoother and less aerobic. It requires much more skill and near-perfect balance, and no one can do it in all conditions. In soft snow, skis merely need a little well-placed pressure to bend into a smooth arc. Tip those arched skis up a little, and they'll carve a smooth, round track--guaranteed, as long as you sustain even pressure over their "sweet spots." Trust them as they dive straight down the hill; stay with them, and they'll slice smoothly around a complete, round turn. Relax, tip them the other way and return the pressure, and they'll repeat a turn in the opposite direction.
The only real difficulty--but a VERY real difficulty it is--is maintaining balance, which is critical for accurately tipping and pressuring the skis. If you lose your balance--get too far inside, for example--you cannot twist or displace your skis beneath you to recover. So you need extraordinary balance. This means quick and refined reflexes (see those "epic" threads of midwinter with David M) as well as highly developed movements and perceptual skills (the ability to read the snow and make appropriate movements "proactively," minimizing the need for reflexive recoveries).
This second (carving) strategy works best with a fair amount of speed, and on slopes that aren't terribly steep. There are several technical reasons for this, which I won't get into at the moment, but most skiers are intuitively aware that you can't sustain pressure and "carve" the upper half of a turn on very steep terrain. So my usual strategy in typical breakable crust involves a blend of both techniques. I don't leap my skis out of the snow and throw them sideways, but I relax and let them rise out of it at the end of the turn just enough to let me redirect the tips down the hill. Then I try to let pressure build smoothly and progressively through the second half of the turn, carving as much as possible, and sustaining the pressure as long as I need to finish the turn. When the turn nears completion, and I sense the pressure at its maximum, I begin to relax again and let the skis rise out of the snow, steering their tips down the hill again when they surface. At all times, I try to keep the skis going the direction they're pointed. When they're down in the snow and carving, I let them go. When they're out of the snow, I steer them carefully so that they're still moving forward when they return to its unforgiving grip.
Finally, or perhaps it should have been first, if you tend to ski in a taller, relaxed "skeletal" stance, lower it somewhat, to tighten it up a little. This is a good idea in any sort of inconsistent snow, where you can expect to be thrown around. A more muscular stance keeps you from being knocked around as much, and quickens your response when you ARE knocked around.
It's not easy. Everyone gets knocked around, at best, in breakable crust. But a few linked turns in the stuff can be highly rewarding, and even, yes, fun! Don't expect complete consistency, ever. You will fall in it now and then--that's part of the game. It's a real challenge. But breakable crust can be very, very good