Could Someone correct my "letter" please?

As part of my English final I have to write a short "letter" to a teacher that has been inspiring to me. I'm horrible at writing letters so I would love if someone would correct it for me. Thanks ^^
Here it is:

Dear Mr. Rush,

I really enjoyed taking your art classes in 7th and 8th grade. They were some of the most memorable classes I have ever taken. You encouraged us to be creative and think independently, something some teachers don't do. I learned so much in your classes. I learned how to become a more creative thinker in your classes. We had a lot of class discussions, instead of reading out of the text book all the time. You told us about many different artists like Van Gough, Monet, and M.C. Escher.

We did a lot of projects and I learned how to many different forms of art. My favorites were printmaking, and using oil pastels. You also taught us how to draw proper proportions of the face and body. You even how to draw buildings. All of these projects helped me to finish my art and my drawing skills got much better than they were before. I learned that practice makes perfect.

I also really enjoyed your class because it was so fun and relaxing. You told us so many stories, and you gave us a lot of time in class to work on our assignments. There was never a time when we were not doing something productive in those classes. Most students love when a substitute shows up for a class. With your class it was the complete opposite. We hated when we had substitutes. The only down side of your classes was that most of the students didn't take the class very seriously and sometimes it affected how much we got done. But overall I really loved your classes. I would definitely take your classes again if I could.

Sincerely,

Nichelle