The veil effect
Translucent screens, whether designed as such or just haphazardly working that way, are among the most definite visual layers. These let light through, but not a clear view of what’s beyond, and there are degrees of translucency. The kind of fabric that covers a softbox for a studio light isn’t much use, but something more open, such as a thin cloth or condensation on a window (or even a pattern of raindrops), has more possibilities. The distances between camera and screen, and between screen and subject, also affect how much detail you can see.
The two key controls, however, are the aperture (for depth of field) and where you focus. There’s no hard and fast rule for this, but it’s worth thinking about whether the screen or the distance will read well when out of focus. In the photo below, the delicate screen didn’t read at all well when blurred, but keeping it sharp enabled the sitting couple and the scene beyond them to be understandable, while also adding texture.