Hello! I am studying to be a high school teacher and I found your art work while researching artwork for your age group. I think your use of shading is very impressive. I also agree with angry waffle about your smudging. I like to use kneeded erasers to remove smudges. It also looks like you are using a softer style of drawing paper. It is good to shade with but is really easy to smudge. Try different types of dry medium paper. Look for paper that is intended for sketching with drawing pencils if that's what you like to work with. You want a type of paper that feels more flat when you touch it with the pad of your finger. I've used the type of paper you used and it's not my favorite for sketching. The strathmore brand of paper is good, You can find it at michaels and it 's not too expensive.