V2 (both sides)
Although this particular type of skating motion in cross country skiing is pretty much the most balanced type of skating motion that a skier can learn; in turn, it is also one of the most difficult motions to master over a long overall distance of use. This motion actually involves using a double pole motion as well in order to increase overall balance. It is also important for skiers to use this double pole motion on each and every actual skate glide that they do (on both sides of the V-skate). heliskiing
In order to do this particular type of skating motion, you should start off in a way that is pretty much the same as the V2 alternate type of movement. Try to focus on compressing the double pole movement and then immediately recovering your skiing poles. Even though you are immediately recovering your poles, you should still be gliding on your original gliding slide. At the moment that your poles return to the right position, you should then begin the next sliding motion (on the alternate side). Heli-ski
The hardest part of the V2 motion is being able to balance long enough (while gliding on one ski) to get your arms in position to pole on both sides of the V-skate. Most folks will find themselves doing fine for a couple strokes and then all of a sudden their balance goes south and they start doing a V2 Alternate--meaning they start to simply pole on one side of the V-skate and just glide on the other side. V2 is a fantastic technique for flats and gradual uphills as it provides a "middle gear" between V2 Alternate and the V1.
Diagonal V Skate
Occasionally, conditions or individual fitness or just a wicked steep uphill will make the V-1 impossible. On these steep sections you can either use the classic Herringbone technique or you can use a combination of the classic Diagonal Stride and a basic V-skate.
Diagonal V-Skate simply involves V-skating with your legs while using a single opposite arm-opposite leg motion with the upper body. I find students learn this technique fastest when they think of a "one-one-one" verbal rhythm as they combine upper and lower body motions. Once you get it going, this is a really easy technique and a great way to get over just about any size hill.
This is the technique American Bill Koch rode to the 82' Overall World Cup title and consequently, the main reason why XC Skiing involves as much skating technique as it does today. Although marathon skating is not as common as it once was, this is a good technique to have in your hip pocket for certain conditions.
Start with one ski in a Classic track and place the other ski at a slight angle away from the direction of travel. You then use the angled ski to "scooter" the ski left in the track while simultaneously utilizing a strong double pole motion. Make sure to really get your body over the pushing ski to maximize the power of both the pushing leg and your upper body. This technique requires very little balance compared to most skating techniques and can be a very nice learning drill.