Becoming a professional dancer does not simply entail dance lessons. I found myself having to immerse every aspect of my mind and body in all areas of training in order to properly prepare myself for a professional career in classical Ballet. Obviously Ballet or dance classes, which teach technique, basic knowledge and develop ability are important, but your body and mind also need further training to be able to fully achieve. Ballet is more than steps. I found that it could be broken up into the following categories: strength and stamina; flexibility; technique & understanding; musicality; and performance.
Strength and stamina can be built up in a variety of different ways. However, even if you are dancing 6 or 7 times a week, it is unlikely that the dancing will be intense and ongoing enough to truly develop the strength and stamina required. I found a regular run built up fitness and swimming increased my stamina. I also completed several back and leg exercises every evening: lifting my leg from a stair banister without using my hands 10 times each; lying face down flat on the floor and without using my hands, lift my head and upper back up to reach 90 degrees to the floor. You mainly need to build up back muscles and leg muscles (although avoid upper thighs).
Flexibility is harder to attain. Some dancers will be naturally flexible and will not struggle to sit in the side splits, box splits and have great turnout. I was never one of these lucky people, but still I was able to attain a high enough level of flexibility. I sought out a gymnastics coach who I visited once a week for an hour. He would help stretch my muscles by holding me in positions (supported splits position, for example), gently exerting pressure. I would then repeat these exercises, slightly less aggressively, at home by myself each night. After a couple of months I found that, despite the pain and discomfort that the stretching caused, I had achieved the flexibility I had desired. I would advise seeking professional help with this area, as it is so easy to do permanent damage to yourself if you do not fully know what you are doing. That would truly destroy a future career in dance!
Technique and understanding I felt was mainly covered in my dance lessons. Of course, the more lessons you attend, the more and quicker you will learn. Also, completing exams (for example with RAD or Cecchetti, such as Grade 6, Intermediate etc) makes you learn theory. This gives you a greater understanding of the technical terms and what is meant by them, helping you to transfer this into your dancing and achieve greater technique. I would also advise having classes with more than one teacher, as each teacher will have a different way of teaching, correcting and explaining things. Each teacher will also have different experience and training to help you. This way you ensure a much broader understanding of Ballet.
Musicality is a slightly more abstract part of dancing. Some dancers are very gifted and are naturally very musical, yet I do believe that much of it can be taught. Dalcroze Eurythmics teaches musicality and timing, and if you really struggle with these aspects of dance, I would suggest you try and attend classes. More simply however, and possibly more fun, would be to learn a musical instrument. This will teach musicality and timing as a mater of course, as well as opening your ears up to the appreciation of music. The worst thing to watch on stage is a dancer with no appreciation for the music that their choreography is set to. I believe that getting involved in the music via an instrument is the best way to avoid this.
Finally, performance is the icing on the cake. No matter how perfect someone dances, without an air of performance, it can be drab. Try and create mood and a character for yourself whenever you dance, even in class! Put emotion and feeling into every movement. Some dancers take up acting classes to enhance their performance; others write stories to match any choreography in order to direct their performance. I find the best way to perform anything in dance is to concentrate on a combination of the music (what mood does it portray?), the context (am I dancing in character? How do I feel?) and every tiny aspect of your movement (even the smallest curv e in an arm or tilt of the neck will change the performance). Ultimately, performance will come if you are proud of what you are dancing, feel confident and most importantly, are enjoying it.
Becoming a profesional dancer will be one of the hardest things you ever strive for, but it will also be one of the most rewarding. At the end of the day, if you love it, then it is possible to achieve.