Hi all, thank you for your comments, I really appreciate.
@Proximocoal contrast is the one thing I still struggle a lot and feel my skill is still very inconsistent. I can paint a model where I really get the contrast right and I am proud of the result (keeping in mind I am no pro/competition painter) and the next model I might feel like it is impossible to get it right.
Skin in particular has been giving me some trouble because I've been switching my paints from GW to P3 and I find the P3 skin tones too pinky. I literally only learned a few weeks ago that I need to mix green in there to cancel the pink in a natural looking colour. Also, the highlights are not easy to get right, specially on the face, without looking like the miniature is using make-up.
I will continue practicing.
@monkeyboy for the denim, I find the easiest colours to use are GW shadow grey for the mid tones and space wolf grey for the highlights. On top of that I use slight variations for each model. On one I will shade it towards blue mixing P3 exile blue and/or black, on another I mix a bit of P3 coal black, etc. For highlights sometimes I go towards white, sometimes I just keep it blue-ish/greyish. But just by starting with shadow grey it will already look like denim.