the only way to become good at arty things is through practiceyou always have to get through the bad stuff to become good
just go back to what you have already made and add onto it, or update it.most nicer builds arent always done from ground up, sometimes people start with basic shapes, and complete a build before they go back and add more details.
I don't agree with the whole idea of practice. You're either creative or you're not. I wouldn't say I build too much since I'm only on like a few hours during the week, but when I do I create beautiful builds like my basketball arena out of nowhere.