Fundamentals

So, over the weekend I was looking in my sketchbook and I realized that my shading is good, I spent a lot of time practicing and learning it especially because I enjoy using pen. But I was looking at the shape and just seeing how the actual foundation of my drawing is, and I realized that it isn't that good. Not to put myself down just like honestly giving a opinion, and now I have to practice the foundation/fundamentals of drawing because I know if I learn my art will excide to a different level.