Students draw their design first on copy paper, tape it onto the scratch paper and trace over all the lines with a ballpoint pen. This will transfer grey lines onto the scratch paper. Then they scratch away with their chosen tool. For this project I left the subject matter completely up to students- I like this lesson for the end of the year or right before a holiday as it's simple yet fun and keeps the kids engaged.
Some Grade 7 - 9 finished works: