My boys both participated in their elementary school's fifth grade "biography tea," where they had to research some famous person and then impersonate him/her at a fancy tea-party. From that assignment I created my chapter book Being Teddy Roosevelt.
For another assignment they had to keep diaries in the persona of pioneers heading west on the Oregon Trail. That became a central plot line in The Trouble with Babies, where Nora is appalled when she draws a "fate card" for her Oregon Trail adventures that has her "married" to class bully Dunk.
On school visits I haunt the hallways to peek at student work. I was thrilled to see a bulletin board full of ideas for how each kid would change the world. I scribbled down some of the kids' actual answers in my trusty notebook; they made their way into How Oliver Olson Changed the World - which also featured the "third grade space sleepover" my boys attended.
Next time you're stuck about something to write about, wander over to an elementary school - or wander vicariously via Pinterest - and see what fascinating activities inspirational teachers have invented. Each one contains terrific material for a story. In case children's authors needed yet another reason to be grateful for teachers, this is it.