Observe the breath closely. Really study it. You find enormous variations and a constant cycle of repeated patterns. It is like a symphony. Don't observe just the bare outline of the breath.
Every breath has a beginning, middle, and end.
The depth and speed of your breathing changes according to your emotional state, the thought that flows through your mind and the sounds you hear. Study these phenomena. You will find them fascinating. No, that is not Vipassana. That is thinking.