This is a great lesson that can be adjusted based on the level of the students. I do this with all my 3rd, 4th, and 5th graders and I'm able to differentiate it enough to fit all of them. So here's how it came out:
I make it a little different for my fourth graders by making them identify whether the words are verbs, nouns or proper nouns as we brainstorm. They also have to think of more words to describe the noun they choose for their snowflake.