As a data creator, you have certain rights over the work and an opportunity to license your data appropriately to facilitate sharing and re-use. The application of copyright and licensing depends on several factors - whether your data set contains quantitative data, qualitative data, or sensitive information. Copyright and licensing options vary depending on the type of data and its sensitivity.
If you are re-using data created by other pay careful attention to the license that material is released under. It may restrict what you can do!
The Creative Commons licenses are frequently used for sharing academic data and can be widely applied to all sorts of outputs. The Creative Commons CC-BY license is often used for open access publishing but there are a range of licenses available to cover different use cases.
If you are sharing data openly and are not worried about copyright or intellectual property ownership, consider using a public domain dedication to make your research data free from any restriction for re-use.