I mentioned the financial aspect of a plan earlier, so let me add this. Another fact about financials to consider: not all business activities are about making money. Point being, in most enterprises financial considerations are centric to the document. But there are some other considerations. For example, a few years ago I wrote a plan for a new subsidiary that was focused on developing an inventory of patents. The potential financial returns were years into the future. Those patents may or may not ever have commercial value. Another example is a non_profit enterprise that has need for a complete roadmap for growing their profile in a market, of which a marketing plan would be the centerpiece.
I don't know of better way than to let your business give you what you want for your lifestyle. Whether it's a sample business plan for a small business or one where your business gives you a plan, it should tell you what is needed to take you where you want to go and when and how you can get there and it should be in clear simple terms, supported with all the specifics. So using a sample business plan for a small business is just one of many ways to make a business plan but frankly I think designing one that will have your business give you exactly what you want is by far the best way.