I often commit the awful compositional crime of cutting off at ankles and wrists. I try to get as close as possible to the dancers (ie, fill the whole frame with their body). It's a trade off: if I'm further away, sure I'll get the whole body but the resolution will be worse than if I'm closer up - there's more light and more detail captured. But I sometimes misjudge dancers' full extension and some body parts disappear from the frame. And toes and hand positioning is an integral part to ballet!
The best angle to photograph dance, I decided, it straight on, eye level with dancers' torsos. I think this is because ballet was developed to be viewed from this angle. The aesthetics are optimized for an audience at mid-level. If I'm too high up, the jumps and vertical extensions are less dramatic. Too low and it's awkward to see the undersides of everything. To get this straight on view from the front however, I had to stand on the arm rests of the second row theater seats. I couldn't stand on the seats as they were the flip-up type. Arms rests seemed only slightly less risky. So yes. I spent most of my photographic time perched on 2 slick, skinny, non-padded brass arm rests, in socks. These are the risks I take to achieve the best angle.