Ask students to write an essay on a given topic.
Choose judges from outside the school to read the pieces and pick winners
Award a pizza party to the classroom with the most writing contest entries.
Ask local businesses to donate prizes. Prizes can go to one winner from each classroom or each grade.
Describe the person who has had the biggest influence on your life.
What questions would you would like to ask animals? What would their answers be?
Pretend that there is no such thing as technology. What do you do with all your time?
Describe your favorite day ever. What about it made it special?
Write a book review of your favorite book. Describe why others should read it.
More writing prompts: http://journalbuddies.com/teacher-parent-resources/48-thought-provoking-elementary-writing-prompts/