If you’re stuck, write about writing. A book may be static, but our perceptions are dynamic. https://sarahleastories.com/2016/03/06/writers-digest-wednesday-poetry-prompt-343-theme-poem-about-a-book/
A piece of literature can have many incarnations. When writing such a work, always cite exact quotes, & what work it is based on. I did this with a very interesting short story. https://sarahleastories.com/2016/11/01/poem-a-day-writers-digest-challenge-1-theme-stay-go/
Just as there are numerous genres in which to categorize a story, there are many formats in which to write them. Experiment with some of these lesser-utilized ones. https://sarahleastories.com/2016/09/24/writing-prompt-experimenting-with-hybrid-fiction/
Write a response to another poem, & watch it take on a life of its own. https://sarahleastories.com/2016/04/22/poem-a-day-2016-writers-digest-challenge-21-theme-poem-that-responds-or-somehow-communicates-with-another-poem/
Have fun with the absurd. Have you heard of fractured fairy tales? How about a compound fractured fairy tale? https://sarahleastories.com/2016/02/12/writers-digest-wednesday-poetry-prompt-340-theme-finally-or-at-last/
You can go for a “multiple ekphrastic”—using 3 (or more) paintings as inspiration for a narrative poem/prose. I married that idea with Rudyard Kipling’s “Just-so” type stories. https://sarahleastories.com/2015/11/05/poem-a-day-writers-digest-challenge-4-theme-once-upon-a-blank/