By citing your sources, you:
Most search tools and databases have options for creating citations (they often need some tweaking, but are a good start)
FOR CREATIVE COMMONS IMAGES:
FOR PUBLIC DOMAIN IMAGES:
WORKS CITED FOR A WORK OF VISUAL ART: PRINT OR ONLINE REPRODUCTIONS
Artist LastName, FirstName. Title of Work. Date of Composition. Medium of Composition. Institution Housing Work, City Where Institution Is Located.
Monet, Claude. Water Lily Pond. 1900. Art Insitute of Chicago, Chicago. Artic.edu. Web. 4 August 2014.
Kandinsky, Vasily. Orange. 1923. Museum of Modern Art, New York. WikiArt.org. Web. 25 July 2013.
da Vinci, Leonardo. Mona Lisa. 1503-1506. Oil on wood. Louvre, Paris.
WORKS CITED FOR A WORK OF VISUAL ART: ONLY CITED ONLINE
Artist LastName, FirstName. "Title of Work." Date Created. Editor/Author/Compiler Name. Name of Website. Name of Website Publisher. Medium of Publication. Date of Access.
javacolleen. "Lantern Floating." 2010. Flickr. Web. 2 December 2012.
Elson, John. "4Palmount." 2009. Wikimedia.org. Wikimedia Commons. Web. 4 August 2014.
Section 5.7.6 of the seventh edition of the MLA Handbook for Writers of Research Papers.
The sixth edition of the Publication Manual of the American Psychological Association does not have guidelines for images, artwork, sculpture, photographs, etc. However, here are some guidelines from the APA Style Blog:
SOCIAL MEDIA PHOTO, GRAPHIC, OR PHOTO ALBUM
Creator, A. (Date Posted). Caption text [Medium]. Retrieved from http://website.url
VISUAL ART PIECE
Arist, A. (Year Created). Title of work [Medium]. Location of work: Institution housing work.