A very cool move that is a sticking point for most breakdancing careers. Most breakdancers train until they can do half or one flare but do not put in the work to do continuous flares which places you in the advanced category. Flares are difficult because you have to be very good at a couple of things at the same time; strength, flexibility and technique.
Wrist / Forearms
You need to be handle your bodyweight on your wrists. Learning flares is harsh on your wrists and weak wrists will get injured. This is the most common injury when learning flare and not all breakdancers overcome it. Get your wrists stronger try these exercises here:
After you get wrists able to handle your bodyweight its times for the next higher up muscle to support your bodyweight, your shoulders. This has already been covered so do the work so you don’t struggle with the move and get hurt. To summarize you should be proficient in handstands and be able to do handstand presses. If you don’t know what that is you aren’t ready for flares yet. Below is the shoulder training to be injury free and strong for flares.
Can be done on the ground, if you can’t hold your legs high enough do it raises. Strive to hold your feet above your belly button. Do 10 second holds 3 times a week. This will strengthen your hip flexors so you can raise your legs high in the front position of flare.
The less flexibility you have the more strength you need to compensate. Lack of flexibility makes it harder to perform the correct technique. You want your knee kicking up to your face and shoulder to get really clean flares.
Shoulder flexibility is overlooked in flares. You need to be competent at skin the cats so you have the shoulder flexibility to raise your hips high in the front part of the flare.
The best way to practice the flare is start double leg circle training with the bucket. This cuts the move in half. When you first start training there is a lot going at once in the flare and double leg circle training will focus on hand placement, keeping your legs straight and pushing with your shoulders. This video shows double leg circles:
Once your hand placement and shoulders know what to do, the last step is controlling your legs. Your legs kick again and again in a flare at different times. You can practice leg control by trying the move, but this is the most frustrating way. You can practice parts of leg kicking with your butt on the floor, this is good for the front portion of the move in the beginning but not helpful as you advance. There is a flare drill for working the rear part of the flare that is real good and shown below.
The best way to work the legs is to use a flare trainer that holds your legs then you can perform many repetitions and learn the technique.