Focus on the area that matters for your situation. Business plans take too long to write, are seldom updated, and almost never read by others but documenting your hypotheses is key.
Also, save a few words for how you plan to differentiate your product when going after your target customer base and note for the record that price is rarely an effective differentiator on its own.
Talk up your collective expertise as justification for why investors should buy into your operation. So, what do you need in your one-page plan?
Or if you are writing an internal plan, concentrate on the situation that is most critical, needs the most attention or cries out for change.
For example: What are you building? It feels like we actually fleshed something out without having to write a 20 page business plan!
What People Are Saying "Any startup should use this tool! What you need to do here is crystalize why your business is going to be different from that of your competitors.