As a writer, author, attempting to be imaginative person one of the exercises I sometimes use to get the cogs whirring is the what if game. You may have written a piece you are unhappy with but somehow it just isn't working, so what if the lead character swapped gender, what if instead of going to the supermarket they went into a betting shop - you get the idea. I find the kids play a version of this every day.
Imagine that you are so and so and I am this person and we are doing this, it is interesting to listen as they negotiate each trying to move higher up the perceived hierarchy. Indeed Lucy not protests heavily if she has to be a baby, because as she assets almost constantly; 'I'm a big girl now I'm three.'
It is great listening to them as they swap cahracters, some based on the TV, some from books and other generic characters from the world around them, it gives them the opportunity to explore different points of view and think about how other people live their lives, and sometimes I wish my life could be as easy as their game. When something isn't going right just change the rules, why can't the characters in my book behave like that, perhaps I am writing the wrong story.