>>7582611
ah well mostly just understand 3d forms and how they interact with light, that will help you with yuor edges while painting (hard edges and soft edges)
also paint a lot of clothes and do studies - for example this
https://youtu.be/9rObeBEBkUE
- this might help, i watched his skin painting video to learn how to render

also i would recommend playing around with sculpting software like z brush or blender, it just helps you manipulate forms i guess? not really good at explaining stuff
fucking around with 3d helped me understanding light, materials and shit like that
hope this helps