Choosing the right CC license for a work can be a deliberative and thought-provoking process, but it doesn't have to be. We describe license-choosing in more detail below, but if you want to pick one quickly, Creative Commons has a simple tool for choosing a license based on a couple questions about how you'd like people to use your work.
Basically, when you're looking to share your work with others, ask yourself: do I want to allow commercial use of my work or not, and then second, do I want to allow modifications of my work or not? If you're not concerned about commercial use or controlling modifications of your work (in fact, you'd love it if people made derivative works based on yours!), then you can use the CC Attribution (CC BY) license. If you want to allow derivative works, but require that any derivatives also be made open, you can add the ShareAlike condition.
It doesn't hurt to think a bit more deeply about what uses you want to permit and even encourage. Every creator has specific interests and levels of comfort with sharing work, so it's important to take that into account when making a license choice. One person's pro could be another person's con. Different communities have varying sharing requirements, so choosing a license might need to conform with your community of interest. For example, the Free Culture community only views the Attribution and Attribution-ShareAlike licenses as acceptable for a work to be "free". Creative Commons has been collecting a wide variety of examples of people in music, education, and social justice, all using CC licensing for their work.
Much as we love CC licenses, they are not appropriate for all situations. CC offers a handful of possibilities to consider before you decide on a license.
First, decide what license you think the creator in each scenario would choose. Then go to the Creative Commons license chooser tool and answer the questions like you were the creator.
You are a relatively obscure musician who wants as many people to discover your music as possible, but also wants to be able to reserve the commercial right to sell your work. Which license(s) might you choose?
You are an elementary school teacher who has created a great resource on how the solar system works, and want other teachers to benefit. Which license(s) would you choose?
You are an amateur photographer who has taken photos of landmarks in your area and want them to be featured in their Wikipedia articles. Which license(s) do you choose?
In each case, was the license chooser result the same license you chose? If not, what do you think happened that led to the discrepancy? Did you choose different licenses depending on the type of creator? If so, why? What was different?
Ready to CC license your own work? Try this other P2PU challenge: "Get a CC license. Put it on your website."