Easy to use brushes and textures for subtle noise.
Check out my Ko-Fi at saturns_day for more brushes if you'd like!
Very simple but very useful brushes + their texture. These are great for things that need a subtle texture, like skin & velvet. Please adjust the settings to whatever you like!

The first two are airbrushes, easy to add gentle noise to any art. The third is a more textured brush that works well as a pencil as well as a texture.

Lastly, there's a crunchy texture brush if you need a sandpaper-like texture. It's still softer and subtler than most texture brushes. Raise & lower the texture intensity, size, & blending mode for new effects.
Lastly, here's a preview of the textures. All the brushes used the smoothed texture, but feel free to swap them out.

brushes
textures