Just as clothes make the man, so does art make the story. There is a long and happy history of collaboration between the visual arts and fantasy fiction, all the way back to the beginning. I know that when the well of inspiration starts to run dry, perusing some of the more fantastickal creations of the Western artistic heritage is a good way to get the juices flowing.
The Pre-Raphaelites are a good place to start – part of the Romantic reaction against the industrialization of society, they looked to myth and the mediival past for their inspiration.
Edward Burne-Jones, who began as a Pre-Raphaalite, then went on to become a leading light the Aesthetic movement. Look on the following works from the latter period and tell me they don’t have some kind of effect.
Of course, nowadays we can skip right past the art museum and consider fantasy art as its own genre. Often derided as little more than kitschy covert art (a charge that is all to often true in many cases) nonetheless there are many fine artists working in this field whose works can act as dynamite against an attack of writers block.
Frank Frazetta (may he rest in peace) who virtually defined the modern image of Conan.
Michael Whelan (one of the true greats.) Everyone has at least ONE book featuring a cover of his, even if they don’t know it.
Boris Vallejo, for that old-timey lost-in-the-70′ pulp feel (try getting away with this nowadays…)
And one of my personal favorites, Ruth Thompson. I met her at the New York Renaissance Faire, and been following her every since. Most excellent talent.
Of course, this just my humble opinion, and I make no claims as to actual good taste….