I really have no idea about how much aspiring artists follow my work, for this reason I don't share much about my painting process and such, besides of what I show on the live streamings. And this is the reason I don't have nothing related with this as reward on my Patreon.
Thinking about it I did a custom pack which you'll can get all the files I use to create a piece and the psd files itself. If interested about the behind the scenes of some illustration I did, just request a custom pack like this.
This one is for sale on: https://gumroad.com/l/HgoEI