Check out these resources all about design.
CARP - Principles of Design
Desinging for Everyone
Can you read it?
Make your text easy to read, make sure it's in a location that makes sense and doesn't cover other aspects of your artifact. If you use topic words that other students might not know make sure you define them in your artifact. For example, if you use decomposition when talking about computer science you would need to define what decomposition is.
Can you see it?
Use photos, drawings and/or diagrams that explain what you're trying to share in your artifact. Make sure your photos, drawings and/or diagrams help to explain the topic in your artifact.
Can you hear it?
It's great to include audio in your artifact so people can listen to what you're saying as well as see and read what you're sharing.