Open licensing is the best way to open your publications, and the most used licenses are the Creative Commons (CC) licenses. CC licenses give a right to use the material and you can use different licenses to define, how the material can be reused.
Open licensing does not remove copyright or authorship, and the author of the original material must always be given credit. There are different CC licenses with different rights for reuse, more information can be found on the website (see the link below).
Please note that the recommendations for open science as well as many research funders (EU’s Horizon, Research Council of Finland) require the use of broad CC BY license, which e.g. gives a right to adapt and distribute the material freely, as long as attribution is given to the creator. Publishers decide if they use CC licenses, so especially if your funder has requirements on open science, you need to take this into account in the publication plan of your project. Choose those publications, which have corresponding policy on the use of CC licenses with your project demands.
You can ask more about licensing from address att(a)jamk.fi