This was part of a classroom exercise in my multimedia drawing class. Movement is always a good challenge for any artist, and here the whole painting teeters on making sure the material is moving in a circular shape.
With a dancer, just like a model, you can make the figure 9 head heights, especially when the dancer is balancing on their toes.
I used a varied palette for the colours of the dress, mixing purples from very red to quite blue. I used a flesh tint from a tube for the skin tones, but added some brown for areas of shadow.
To make the material move: ensure you draw a dynamic shape for the swirl of the material. Then you need to use your tonal skills, s0 that the shape of the material around the body is far less transparent then the material that is moving from the knee, right around the back of the body, and back to the front of the garment. I worked in 9 tones of the colours, working both in glazes and wet on wet.
I painted the background wet on wet, using the same palette I used for the dress, but in much weaker washes of the colours. I used pen to draw in the small shapes on the face, more practical than using paint and a brush for small shapes on faces.
For the ballet shoes I used a mix of two colours, the proportions of which were, flesh tint, 70%, to which I added 30% brown.