Can anyone help me with shading/rendering?

[ripe jacinth]

I have been having some troubles with shading/rendering digitally recently, can someone give some suggestions?
I also am looking for new things to improve my art so criticism is needed ❤️

[fast idol]

My biggest tip for shading/rendering is to always think about where the light source is coming from and work off that - pull up references if need be for similar light sources and just think about what will cast a shadow and how different textures react differently to light! The posing on this is amazing my only advice would be maybe moving the left eye down slightly as it is higher then the right one, but if it’s a style choice then it looks good as is. Hope this helped!