This one is also from yesterday, with a white background (slightly lit by a striplight that was on the left) and a striplight to the right. The flow in her hair is from a windmachine, one of my favorite tools in the studio.
These days I only use my black and white paper backgrounds. Black can appear as fully black when using enough light on the model that doesn’t hit the paper. White can go from pure white to gray, like in this photo, which is nice and flexible. Many people don’t realize you don’t really need a gray background, and can just use white.
There’s a touch of vignetting added in Photoshop here (mostly on the top left), but a lot was already present in the original.