Issue: thinking is hard. Students will often find something easy to copy rather than sit down and work though an original idea. That results in sketchbooks full of works that are both appropriations of another artist's ideas (stealing) and devoid of the creative part of the creative process.
Banning copying without explicitly teaching the alternative has never worked for me. Here is what I am trying instead.
1. Stage one:
Using an English essay or song as an example, we work through the difference between tracing, copying, and being inspired by another person's art. When they recognize the ethical issues behind this, we can move to the next stage.
2. Teach the creative use of references and how to find them:
In the Inspiration Board project they start by seeing how many images are used to make a piece of photo manipulation fantasy art and the inspiration board of Google Doodle artists. They then work though a series of steps gathering types of images with the goal of creating a new, original piece of art. At each stage they need to say what they are thinking. This is a Google Classroom activity.
Copy of Inspiration Board CW by M. Collins on Scribd
Here is a screenshot of another and the resulting sketch.
3. Build the habit of using references in creative and innovative ways through repetition and expectations.