Writing a one-page business plan you will actually use
A practical guide for Crazish readers, written from everyday experience.
A business plan does not need to be fifty pages to be useful. For a small venture the most valuable version fits on one page: who the customer is, what problem you solve, how you reach people, what it costs to deliver and how much you need to sell to cover those costs. Writing those five answers forces the vague parts into the open, which is exactly where the risk hides.
Treat the page as a living document rather than a presentation. Revisit it at the end of every month, change the numbers that turned out to be wrong, and note which assumption surprised you. After a year you will have a short, honest record of how the business really works, which is worth more to a lender or a partner than any polished forecast.