Improving my skills

I've been recently trying to add complexity to my artwork, because I feel like that's the next step. In order to address complexity you must first understand shapes. After you understand shapes you must then understand characters and anatomy. Then you must draw a character shape with all the complex shapes that make it unique. My problem is that I can't recreate other people's artwork. Believe me, I tried. And this is why graphic design is a hobby at this point.