You are pretty close in proportions, your character is already 7 heads tall which is fine. Maybe do some practice on looking at the human form and doing a chart like i made here, to visualize how large each part of the body is and how they relate to eachother, example would be the elbows usually lining up with the end of the ribcage and wrists matching the hips. I also redrew your pose to give an idea how you could push the pose further and to think more about constructing your character as 3d forms first while thinking about gesture. Im still learning this stuff myself, so take it with a grain of salt. But your off to a good start! | Artwod Feedback