Most skiers think that they can slow down by edging more on the steeps, but the opposite is true. A high edge angle at the end of a turn will scoot the ski forward and often cause the skier to become out of balance. Combine this with some tension or stress to the downhill leg and the situation can worsen because the skier is moving away from the fall line instead of embracing it.
Although it is true that edging with providing grip, it will also cause the skis to travel across the fall line rather than down it, thus creating a false sense of security because when traverse across a steep slope you are often out of position for the next turn.
Simple fact, edging in the last third of the turn is acceleration because when you pressure on the ski edge in the in that part of the turn, you will accelerate across the slope. When this happens, the skier typically has not enough pressure on the uphill ski, and this causes even more instability. The result will be hesitation to make the next turn especially if the terrain is intimidating.
Here is an example. A skier enters onto a steep slope, and their hips are behind their feet. Then they initiate the turn, and their skis accelerate down the fall line, and the skier immediately puts the skis hard on their edges thinking it will slow them down only to accelerate across the fall line. They repeat this a few times and low and behold their thighs are burning, and their confidence is shaken.
So what is the fix? It is simple, edge less on the steeps. The goal is to get the skis to drift down the fall line rather than traverse across it; to accomplish this add some pressure to the uphill ski at the end of the turn so that the feet are closer together. This will release the edge of the downhill ski, and the result will be controlled deceleration in the fall line.
Drifting down the fall line will also lengthen the turn, which will increase stability. Plus while standing on both skis, the skier will feel more comfortable moving into the next turn. Your balance will improve as will confidence.
Here the few things to remember next time you head out onto the steeps. Start on a steep groomed slope. Stand tall with your shoulders over your feet and your feet under your hips. Then lower the edge angle of the skis to create more surface area on the snow and slide down the hill. Now with some momentum allow the skis to drift down the fall line instead then traversing across it and make a turn.
Do this for three or four turns then add some edge to grip and stop. Repeat. Once comfortable head off to some steep smooth slopes and practice, the goal is a series of smooth medium length turns at a consistent speed with little to no acceleration between turns.
I tell skiers of all abilities that deceleration happens best over a series of turns. Think of it as slow, slower, slowest, stop. When you slow down over a series of turns you are more apt to stay in balance and better manage your control in varied terrain.
The result will be more confident as you explore more steep terrain on the mountain.