What are the key points you want to make?
Is there helpful background information, research evidence, facts or figures that you need to include to make the case? Where can you find this information?
If you’re working to a tight deadline, you may have to make a call about the level of detail you include. What is essential?
What presentation style will you use?
Does the person you are briefing prefer lots of beautiful prose, or do they engage better with graphs and tables?