Imagine what might happen if your character lost something important, such as a wallet, passport, or credit card. How would she react? What would she do?
Would she search through her purse, possibly dumping the contents onto the floor of a store? Retrace her steps? Call a friend to come help?
There are countless numbers of scenarios to play out!
Your task is to write a story in which something is lost.
Have fun with this one.