Create a tale of rising tension in which the stakes are raised with every sentence. If there’s a boy walking down the street in the first sentence, in the next a dog turns the corner and barks at him. The boy starts to run, the dog gives chase. A volcano erupts in the boy’s path up ahead. Okay, that last one maybe got ahead of me, but I didn’t see it coming, and it certainly raises the stakes. See how far your story can go and how fast. This exercise is all about making things happen right away and getting use to controlling how much space you give to each story beat. Give this exercise at least fifteen minutes of your time.
Write it up and see what happens.