A voice memo is enough to get started
Open Voice Memo and talk through everything you want to accomplish. Keep talking after you think you are done. Transcribe the recording, give it to the model, and ask the model to question you until it understands the goal.
The point is not a perfect prompt. It is getting your real context out of your head and into a form the model can work with. Curiosity and persistence matter more than knowing the tools in advance.
What I would add now
The original workflow used plan mode. I no longer use plan mode regularly. The durable part is speaking your goals, providing real context, and learning by using the tools. Read the newer note on X.