First, start with an interesting character or situation like 'A lonely astronaut. He saw Earth from afar. He felt a new sense of hope.' Then, make sure there is a clear beginning, middle, and end in just three sentences. Also, use vivid language. Instead of saying 'The man walked', say 'The man strolled' or 'The man trudged'. This gives more flavor to the short story. Another example could be 'A flower wilted. A girl watered it. The flower bloomed again.'
Sure. Story 1: She found a key. It opened a hidden door. A world of magic awaited. Story 2: He lost his hat. In the search, he met a friend. They shared a great adventure. Story 3: The cat chased a mouse. The mouse hid in a hole. The cat sat and waited patiently.