On the subject of colored pencil portraits, I found this YouTuber to be exceedingly helpful in learning to properly use my colored pencils.
She covers a lot of techniques and what different solvents might do for blending, and she explains the differences between oily and waxy pencils as well as their strengths and flaws.
She also reviews colored pencils and compares them against each other so you know what you’re getting before you buy it. This is huge because colored pencils range so wildly between prices and quality, and a LOT of pencils are rebranded but are actually the same pencil.
I don’t want to buy the same set twice!
So if you would like to check out her YouTube channel, you can find it here.
She also has a webpage with her own coloring books and resources for color matching that you can find here.