Once you apply a CC license to your material, anyone who receives it may rely on that license for as long as the material is protected by copyright and similar rights, even if you later stop distributing it.
CC licenses are appropriate for all types of content you want to share publicly, except software and hardware.
Any given work has multiple elements; e.g., text, images, music. Make sure to clearly mark or indicate in a notice which of those are covered by the license.
CC licenses are operative only where copyright, sui generis database rights, or other rights closely related to copyright come into play. They should not be applied to material in the public domain.
If the material includes rights held by others, make sure to get permission to sublicense those rights under the CC license. If you created the material in the scope of your employment or as a work-for-hire, you may not be the holder of the rights and may need to get permission before applying a CC license.
Prominently mark or indicate in a notice any rights held by third parties, such as publicity or trademark rights. This includes any content you used under exceptions or limitations to copyright, and any third party content used under another license (even if it is the same CC license as you applied).
Consider what you hope to achieve by sharing your work when determining which of the six CC licenses to apply. For example, if you want it to appear in a Wikipedia article, it must be licensed using BY-SA or a compatible license.
Think about any obligations you have, such as licensing requirements from a funding source, employment agreement, or limitations on your ability to use a CC license imposed by a collecting society, that dictate which (if any) of the six CC licenses you can apply.
If you are confident you have cleared all rights in the material, you may choose to warrant that the work does not violate the rights of any third parties.
You have the option of granting permissions above and beyond what the license allows; for example, allowing licensees to translate ND-licensed material. If so, consider using CC+ to indicate the additional permissions offered.
You may indicate particular attribution parties, a URI for the material, and other attribution information for licensees to retain.
You may ask licensees to adhere to your special requests, such as marking or describing changes they make to your material.