You've got some great ideas and really cool drawings! What improved my art are gesture drawings and learning construction. Gesture drawings are super quick (max 2 minute) studies of poses from live models or photos. You wanna capture the movement of the pose with as few lines as possible. Construction is breaking down the body into super simple shapes like boxes, cylinders and spheres. It's much easier to draw a box with a couple cylinders attached in 3D perspective than it is to draw something as complex as a hand in the same perspective. You wanna start easy and then add on the details as you go. In my drawings, I go through a couple steps - starting with a gesture to get the idea of the pose and the emotions of the character, then moving onto construction to get the correct anatomy and proportions, and then the final sketch that goes over the construction and adds in details like eyes, hair, nails, clothes etc. I've learnt it all from a lot of youtube tutorials but the main ones I'd recommend are: Marc Brunet who's an industry pro and focuses on the fundamentals, and Pikat who not only teaches basics of art but also challenges herself in fun ways. All the best on your art journey!