Feedback on head study

I did some rembert montald study recently and i try to apply what i've learn from that study but i don't know why after learning some new hatching thecnique and did some Skull study i still feel the head is a bit flat, any tips to make the head a bit more 3d??

I'm a beginner

I'm not sure what's wrong with the proportions of the face.

I'm a beginner

I'm not sure what's wrong with the proportions of the face

Batcave design

I feel like I can't get the comic feel, my ref was Greg Capullo, Batman Court of Owls, also I feel like I'm lost in the 3d space

citrus reference sheet

something just feels so off about him, maybe its the pose maybe its the proportions i have no idea why he looks so constipated

Creature portrait practice

Here it is after receiving feedback! I’m so grateful for the advice and I’m so much happier with this piece <3

Sunset clouds

I tried rendering clouds for the first time, but i feel like the form ,highlights and shadows of the clouds are all over the place , any tips to improve will be appreciated 😊

Portrait copy of JSS

Everythinh looks off

Character sleeping in the woods

How could I improve/fix it? I’m planning on redrawing it so I would like to know what should I work on in the next drawing of the same idea