Working from Kathrine Wright's Why Write a piece that deals with a specific rationale. You can use this assignment to inspire your yawp piece or to advance an existing story.
For the yawp one, write anything in imitation. The nature of this piece kind of gets at some of what the yawp assignment suggests.
To advance an existing story, here's one way to do it (there are countless)
(Say this first paragraph is your existing story)
After Israel, we had changed me and Sammy. We came back with a souvenir unintended, like an overstretched sweater, we fit wrong. I tried to imagine that it would dissipate, that we would wear it off the way skunk musk--over time, with effort--could be diminished. But it was with us and it lingered.
(Incorporating the Why assignment.)
Because of that Saturday when we found the bottle tree, because of Aster, the harvest still sleeping in the garden, because of the snowfall that first January together, the avalanche that followed, because of eleven more Januaries, the dozen years folding over like ribbon candy with their ups and downs and rippled sweetnesses and brittleness.