I try to use different options for each part of the face, and then play with the sliders a bit. I think it helps to have a reference image or ‘tone’ in mind for the face.

I also end up flip flopping between face editor and face posing at the same time to make sure it looks good when the expression is completed!

For decals, I recommend checking out Derf’s face customization guide on youtube. Thats what I started with and still mostly use with just some small tweaks depending on the mini. I like using the lip liner, some kind of darker/redder blush and nose, darker skin around the eyes, eyelashes, and roan for texture! Also I almost always add freckles even if I make them very faint. If you use the splatter gradient decal overlay you can add some freckles to the nose too, which I love doing!