I searched on YouTube just now and found over a dozen flare tutorials. To bring something different, my goal is not to make another tutorial, but to address the main problems which people learning this powermove face, and to provide solutions for its major gotchas. Therefore, my flare tutorial assumes familiarity with the general flare. I will produce a video tutorial in the near future, which will go more into detail about the following points.
Terminology: I spin counterclockwise. I will refer to my left arm and left leg as my dominant side, and I will refer to my right and right leg as my nondominant side.
Tip #1: To gain a more powerful initial sweep, make sure to not kick the nondominant leg up until the dominant sweeping leg almost makes contacts with it:
Notice how on the right image, my dominant leg, now moving quickly, almost makes contact with the nondominant right leg before the right leg starts to kick upwards. This is important because when entering the V shape in the front, we want to maximize the distance which both legs travel. The more distance we apply force to, the more momentum and energy we have. Avoid swinging the legs at the same time, or else we dampen the torque.
Tip #2: Keep the dominant leg raised as you reach the back.
In the left picture, see how my dominant leg is hoisted straight up into the air? This is absolutely necessary. If you do not persist in keeping it up, then your torso follows, and your flare will become low in the back. Basically, the range of movement of your dominant leg ends in that position, but once you reach it, you must keep it raised, even if it swings no further.
Tip #3: Swing the nondominant leg as hard as possible.
This is an integral, tricky step. I will emphasis this as much as possible in the video version of this tutorial. Basically, the term "nondominant" leg is a misnomer. When proper flares are done, the "nondominant" leg must be swung as hard as the dominant leg is. However, while the dominant leg travels forward, the nondominant leg must travel backwards. That is what makes it tricky: it's an unnatural direction to apply a lot of force in, so it will take quite some practice before we are accustomed to doing it. See how the right leg in the first image is blurred? That is because it is in motion, and I am swinging it BACKWARDS.
Tip #4: Lean onto your nondominant arm as you PUSH the ground with it.
The leaning motion is shown in the second image. Notice how here, I approach the back while taking into account Tips #2 and #3. My dominant leg remains held up high, while my nondominant leg is travelling behind me. I push as hard as I can with my nondominant arm now, in order to elevate my body as I get ready to perform another flare.
Tip #5: Follow through with the dominant leg for another round.
If the previous steps have been successfully completed, then you will have finished one high flare in the back, with the right leg swinging upwards into the second round of flare. In the upcoming video, I will demonstrate why exactly the end of the first flare must necessarily flow into a second. But, in order to continue flares, we must swing the dominant leg another time. This is tricky for beginners. Why? When we began to train flare, we always start from the initial standing position, honing the technique of our first flare. We have always been accustomed to swinging the dominant leg from the ground, comfortably springing off of it. Now, we must wean ourselves from this comfort. Note how when we do this, we now lean again onto the left arm.
What makes the flare more difficult than other beginner moves is that there are so many things that have to go correctly at the same time. It will take time, but as you practice, these correct tips will change from things you consciously emphasize to unconscious muscle memory. Good luck!