If you have any co-authors, you can license only your contributions to the work, unless co-authors also wish to license their parts. Co-authors should agree to and understand the legal permissions offered by open licensing but also the ethical risks, privacy considerations, and rewards of working in the open. Before choosing a license, everyone involved needs to understand the terms and implications of that license.
Authors and co-authors should consider why you want to share the work and how you hope others will use the work.
How much freedom do you want others to have when using the work? The permissive scale on this guide's home page might help make this decision.
Think about any obligations you and co-authors might have or limitations on your ability to use a Creative Commons license that dictate which (if any) of the Creative Commons licenses you can apply. Your unique circumstances might make it necessary or helpful to consult WashU’s Intellectual Property policy.