Skin & Hair are a challenge
That's why most of my local Copic Marker and colored pencil classes revolve around skin and hair techniques. Even when you get good at blending beautiful faces, there's always room for improvement.
The above image is blown up significantly (the actual image is only 3 inches tall) but it shows how many odd and non-skin colors go into rendering a somewhat realistic face. This is by no means photo-realism but my students are definitely working their way towards jump-off-the-page accuracy.
Internet information on Copic markers can be very misleading.
A quick Google search of "Copic Skin" turns up thousands of hits; the vast majority are marker recipes.
"Perfect skin, EVERY TIME!", "The only skin recipe you'll ever need!", "Best Skin Colors!".
Wow, it's like the side show area of a rickety carnival that rolled into town at 2 am.
Stop collecting recipes!
You don't need a binder full of 402 blonde Copic Marker recipes.
You're wasting your time bookmarking every blog post or YouTube video entitled "How to color skin".
Coloring beautiful skin and hair has very little to do with marker selection.
Here's the uncomfortable truth: the key to beautiful skin and hair is knowing where to put colors.
And I don't mean where to put E11- I mean where to put a mid value slightly desaturated flesh tone versus where to put a full shadow flesh tone or a mid tone slight light.
If all that is gibberish to you, you're in the wrong skin class.
Coloring anatomy is all about getting the right value in the right spot. And about putting enough color down. And about stopping yourself from blending it all away.
And then you practice.
And practice some more.
Because if we could magically zap Michelangelo into your craft room right now, and if you asked him "Hey Mike, you're pretty awesome at skin and hair! How'd you get so great?"
He'd laugh and list about 500 things he totally sucks at.
Seriously, no one makes art at the level they want. No one is as good as they dream of being. We are all working on 14 things to improve, each and every day.
So no, there's nothing in your big book o' red-hair marker combinations that's going to make your pretty-girl images sing.
You need anatomy based coloring lessons.
Actually, you need more than one lesson.
And you need to stick with 'em.
And then one day you'll wake up and kind'a impress yourself - just a little.
I'm teaching another class on skin and hair this month.
Because we all need the practice.
This one happens to be a private group, but similar classes are available.