I'm drawing shoes (one hundred pairs in five days) for a book. I know more about shoes than I ever thought, before I started drawing them. They're very familiar, I guess I observe them without thinking about it. The problem is I tend to draw them pointed in the same direction, maybe because I'm right handed. I just don't know. But I have the same issue with noses.
No two the same.
You'll grow into them.
If it's not in the window it may be inside.