Write a letter to the local press from the side character

Write and article responding to that letter

Write about your characters on holiday. Where did they go?

Write the text of an online dating profile for the antagonist.

Think about which people the main character would invite to a dinner party if he could invite anybody, dead or alive. 

Write a diary entry as if you're a side character

Describe the main character's funeral

Write a postcard as if you're the antagonist on holiday.

Write a chapter as that person looking back from ten years into the future.

Write a newspaper article as if you're reporting the events in the story so far.

Pick a fiction book from your shelf. Go to page eight and find the eighth sentence on the page. Start with that sentence and write an eight-line poem that connects in some way to your work-in-progress. For instance, write from the POV of a character, or set the poem in a story setting. Don't worry about poetry forms. Just write eight lines of any length that flow and explore some aspect of character, setting, or theme.

Set a timer for twenty minutes and use at least three of these words in your draft. Write without stopping: a red scarf, windshield wiper, chrome, doily, blowtorch, spatula, CD-ROM, postage stamp, frittering, static cling, radio silence, kismet, calamity, heartburn, bandage.

Close your eyes and write down four adjectives at random. Now write down three nouns. Now write down two verbs. Now write down one adverb. Now open your eyes. Your challenge is to write a 500-word short story based off of these ten words.

Write a presidential speech about why your country needs more ice cream.

Have you ever read or watched something with an ending that left you unfulfilled, unsatisfied, or frustrated? Now write a proper ending that fixes the story for yourself. Keep in mind the components of a narrative arc's resolution while you're doing so.

You are talking to a blind man who asks you to describe the color of the sky. Write down what you would tell this man without once using the word "blue" in your explanation.

Write a short story of whatever topic you'd like, but make sure that somewhere in there, you include this line: "I can't believe that you stabbed me with a knitting needle.

Write a review of a restaurant at which you recently ate. Describe the food as much as you can. Feel free to be eviscerating as well.