This is a form I've used that has generated some wonderful student feedback, and it also has served as a collection of nice memories from the year. This is a way for teachers to reflect professionally. It's a front and back form that asks students about their experience in your class with specific questions. Depending on the students you have, it should take approximately 30 minutes, maybe a bit more if the students have a lot to write.
I also left the file unlocked so that you can add your own name or any other questions you can think of. If you have a question that you find to be successful, please share it as a comment.