This is now a pet peeve of mine when I see performances: when someone's hair is in their face while performing.
The mysterious vibe
I think that some people think that it makes them look mysterious, maybe even mischievous And it can do that to a certain extent. But the problem with the hair over your face is that I don't see your whole face. So when you're making facial expressions, I miss half of what is going on. Believe me, you can have that mysterious vibe without hiding half your face: it's all in your facial expression. ;)
Presenting the wrong side of the face
What I see happening often is presenting the wrong side of your face to the audience. So your hair is heavier and covering your left side of the face? Well, then, if you will be showing your left side to the audience either sideways or at a diagonal, I will lose even more if not all of your face. So you're essentially hiding behind a wall of hair. Believe me, I know how scary it is to perform but please don't hide your face. This will be even more pronounced if the dancer is doing improv, as it will be natural way of sheltering yourself.
So if you know which side your hair is thicker and tends to fall over your face the most, you should know to generally present the other side to the audience the most. It takes some practice but it gets easier with time.
It's really about the sides
The sides of your hair (i.e., the hair in front of your ears), will be the hair that will have the highest tendency to fall over your face. So this is really the area of hair that you will need to pay attention to. Assess what the pattern of your falling forward is like and that will give you an idea of how you can correct the forward tendency.
For all that you love your loose hair, you can gently/loosely pin it in place so that it still keeps its shape but not move so much. It's all about the bobby pins! You can put on as many as you want or need as, from the stage, no one will be able to see. You can also use decorative pins, barrettes, fascinators, etc. to distract from the bobby pins and to add some interest in your hair.
I discovered pomade thanks to a workshop with Michelle Manx. I've been using it ever since. If you don't know about pomade, here is what it does: it helps smooth down the stray hairs. So when my hair looks all messy, just a little pomade in my hands and gently manipulating my hair with my hands in place helps keep the runaway hairs in place. You can also use a little more to shape the hair in place, provided that you're not looking for volume but a sleek finish.
It's really a frame
Essentially, what this is getting to is framing your face to showcase the emotions that you'll show on your face (and all your beautiful makeup :p). So it's not just about getting the hair out of the way but also coming up with a pretty frame around your face. In time, you'll find what works well for your features. Play with it. Practice doing your hair and different ways to place your hair... remember that it's not just about the back of your hair (which you'll be showing only so often) but also about how it falls around your face and what it does for your features. Make sure that the frame doesn't go over the beautiful picture that is your face, m'kay?