Symbiartic recently mentioned tagging science artists on Twitter as an easy way to give credit. Tagging the artist is a great idea, of course, but not everyone is on Twitter. Is there a more general method for social media attribition? Why yes, there is!
Twitter's tidy 140 characters do not leave much space for even a small credit, of course, leading many to simply leave it out. But Twitter's attached image files are essentially limitless. Pasting credit and associated information directly on the image itself takes little time and has no space restriction.
As way of an example, consider Diego Delso's lovely photo of a Khmer Temple uploaded under a Creative Commons license:
To add a credit without altering the original composition, just add blank space under the image to write in the authorship data. In photoshop, this is done with the "Canvas Size" dialogue found in the "Image" menu. Like so:
Our new credit bar can hold attribution details and licensing information, and the file is ready to share on social media.
As a caveat, remember that giving credit is not the same as obtaining proper permission. Images not in the public domain or licensed under Creative Commons may still require prior authorization to share.