If flash is permitted and accepted at the venue:
Assuming theatrical lighting bright enough to get you close, but not enough for consistently good results you'll want to supplement the lighting. You'll be using high ISO.
Try to keep the character of the existing lighting. Take a few test shots to determine the color balance. If it's reasonably close to 3200K, I usually gel the flash with a 1/2CTO to color match the lights.
My goal is to add a bit of stopping power, and lift the shadows enough to get a good histogram.
Set second curtain sync for the strobe. With that, you can drag the shutter (use a lower than normal shutter speed) to capture the ambient light while using the strobe to get crisp(er) details on the model. Light trails from the model will be behind so they won't obscure detail. If you catch them when they strike a pose you can get solid shots.
Setting flash power can be a problem. Auto exposure will fail with black/white/reflective subjects. I've had better luck with manual camera exposure. If my shooting opportunities are all around the same distance I'll use manual flash exposure at least one stop underexposed as a fill. I'll start low and add power until I've got 'enough'. Generally I'll get a good exposure without a flash then drop a stop of ISO and make up for it with the fill flash. I'm trying to get more dynamic range and margin in post via lower ISO, with the desire for low flash power to keep the direct on camera flash from making the shot flat. Also, the flash power often winds up at 1/128th or 1/64th further cut by the gel so the models don't notice it more than the bright continuous lights.