This is a very effective drill to work on your edge feel, balance on your edges, and clean carving skills. This drill is also very effective for good separation of the upper and lower body and brings the focus on turning with the lower body and edging. A good focus on foot tipping is important, especially with the wider stance of this drill, which makes the foot activation harder.
Get in a low or high tuck. Widen your stance or not, as appropriate for the tuck and your comfort. It is good to start this in a low tuck first, as many beginners don't actually flex at all for a high tuck.
Bend the knees ! A lot !
As you start to go down the run, roll your ankles and tip both boots to their left set of edges and wait for the skis to turn. All you do is tip the boots from one set of edges to the other, making sure the upper body is stable.
Note that for this drill, you will keep your body centered between the two skis and put equal weight on both skis throughout.
Especially if you are new to carving, focus on the feeling of slicing the snow, carving the snow, as opposed to skidding in any way.
Also, note that you must focus on tipping both skis together and the same amount - the shins must be parallel throughout the drill.
Here is an example - you can start much slower and ramp up the speed as you get used to it. Use the terrain to manage speed - start on the flattest runs you can find to go as slow as possible, so you don't have to deal with speed control while carving before you master critical speed-control skills:
This is the quintessential carving drill - racers do this ad nauseam. All you do is roll your ankles to tip your boots from side to side, lifting the outside edges from the snow and feeling the inside edges engage.
Windshield wipers are a drill or rather a cue used to enhance maintaining parallel shins, which is a very important aspect of good skiing. As you roll the ankles, engaging this or that set of edges, the knees will move side to side and you'll focus on maintaining the shins parallel ensuring the skis are tipped the same amount and carving together.
Note that you may hear the rollerblades drill sometimes called "windshield wipers".
Here it is again, progressing into tuck turns:
The more you tip them on edge, the faster they turn, see this version:
Ramp it up as much as you can, as long as you keep it clean... here's an example from an 8 yr old, wow:
Sessions to work on carving: