WHOA BIG FILE I'M SORRAAAYYYYY
So here it is, my process. I hope it's easy to understand. If you have any questions, please be sure to leave a comment and I'll do the best I can to answer it.
Clip Studio Paint Pro : www.clip-studio.com
^ A program very similar to Sai and Photoshop combined. There's also a mac version! Yay!
And this will work in all versions of Photoshop I'm pretty sure.