The following is a ppt of 71 Creative Writing Prompts for high school students. Each slide features a single prompt, sentence starter, idea or a scenario for a creative writing exercise.
Suggestion: Besides displaying the prompt as a ppt on the screen, these can be printed and made into flash cards as well.
For my classroom, I printed this ppt document in color on card-stock paper, with the two slides per page option, and laminated them. This is a great way of making writing flash cards.