When authors sign publication agreements with commercial publishers, they typically transfer their copyright away, for life. Unfortunately, if the author includes figures, tables, or graphics in their paper, they may lose the copyright to those works, too — requiring an author to ask permission or even pay fees to use their very own work.
However, authors can easily protect the rights to re-use their own work! Simply by recognizing the individual figures, tables, or graphic designs as individually copyrighted works, an author can grant permission to themselves, and to the publisher, to use those images — while retaining the copyright in the images for themselves.
How to do it?
First, be sure to include a standard “Reprinted by permission of …” in any caption, table of images, credits, or list of materials.
Second, treat these works as separately licensed works. Post them on your professional website, share them on a website like Figshare, or preserve them in the campus repository ScholarWorks.
You can even get a DOI for individual graphics or data, and you can openly license them with Creative Commons. (Be sure to include the DOI or CC licensing info in the caption.)
Third, if your publishing contract mentions getting permission for some works, make sure that the language is broad enough to refer to your own previously published works. If the contract does not mention permissions, feel free to include a note in the contract, or add an amendment in any uploads with the contract, that specify certain materials are “used by permission”.