Perhaps this might be helpful to you then,
Also, you may want to try “DesignDoll” - It is a program with a pre-built 3D model, while a bit stylized there are some decent options. There is a free version (basically you cannot save your models and poses or input new models BUT I just take screenshots of what it looks like when i’ve found what I want and go off that for reference if i cannot find what I’m looking for or don’t have someone i can take a photo of for my references.)
On the flip side of that, if you’d prefer to make it yourself, try Sculptris! It is a free 3D modeling program that, to me, feels about as close as you can get to actually modeling clay. digitally. I use this often to make head models for myself for various creatures. It’s very simple compaired to the bigger programs which helps it run well on older computers and keeps it simple for the user. (An example of a dragon head i did, https://www.tigerdile.com/store-item/3d-dragon-head-model/ )
Hopefully that helps a little bit
I can’t help you much with CSP as I’m only just learning it myself. (I use SAI, primarily, but i really want to move to CSP. It is just hard to switch over when you are still creating client custom work. Gotta use what you are used to and what will get them their product in a decent amount of time ) Perhaps trying it on paper and then re-drawing it in CSP?