How to structure your system design answer in 45 minutes?

I consistently run out of time in system design interviews, especially the 45-minute ones. I feel like I'm barely scratching the surface of a deep dive before the interviewer is saying 'we have 5 minutes left.' It's frustrating because I know the concepts, but the time management is killing me. I'm looking for an ideal time allocation framework. How much time should typically be spent on understanding requirements, clarifying ambiguities, and defining NFRs? What's a good chunk for the high-level design (components, data flow)? How long should a deep dive on a specific component (e.g., database, caching, messaging queue) be? And then, how much time to leave for scaling considerations, trade-offs, and questions from the interviewer? It feels like I need a disciplined approach to structure my answer and ensure I hit all the key points without getting stuck in one area for too long. Any successful strategies or mental timers people use?