Some kind of noise to use somehow?
This is highly experimental, I made it but don't know how to use this myself. See what you can do with it. Based on old magazine covers.






There's 18 materials: 9 in color, 9 in greyscale. The greyscale is just the transparent texture version of the color versions, they have weird names since I couldn't think of any good ones. Feel free to rename them.
Example using the colored noise:

This was done using a lot of layering effects. For example, here's the gold part of her dress:
Top to bottom:
1. "Navy Noise", 18% normal, clipped layer
2. "Red Noise", 100%, normal. clipped layer
3. Bronze shading, 100% normal
4. "Apricot Noise", 100% overlay, clipped layer
5. Dark Gold solid color, 100% normal.
If you're making any sort of illustration with the color version, you'll have to do some planning on what colors you want beforehand. Experiment with it, see what works best.
Here's me applying the colored versions to some previous art:


The power of overlay layers, painting over an area and using "create selection from area" then using it as a mask on another layer, and clipping layers:
If you can't read that, don't worry, it is a mix of experiments since I couldn't tell what technique looked best. You'll probably make a better one!
One last example. Original on top, greyscale on left, color on right.

color
texture