Now, you all remember Stone Soup, don’t you? In it, starving strangers convinced villagers to add ingredients to their pot of broth, one containing only water and a single stone. As the villagers agreed and added their contributions, the soup fed them all.
So, stay with me here. When writing, the stone is your story idea that you water while you also add ingredients to the genesis of that idea. For example:
Tossing carrots into the pot could = creating characters.
Squash is the setting. You get the idea.