Any casual viewer of the BBC programme, Dragons Den will be aware of how easy it is for weaknesses or gaps to be identified. Depending upon the purpose of the plan, this may, or may not, prove to be critical. It is often easier to recognise such weaknesses and gaps, and be prepared to deal with them, either by noting them in the plan itself, or having appropriate answers available should the need arise.
Next you will need to carefully examine what actually goes into your offering. How many hours does it take to create those one_of_a_kind bracelets? How much does it cost to bake a dozen of your special recipe cookies? How much research goes into "whipping up" a website? Making tangible goods requires space. Do you have room to grow enough squash to actually generate profits? Are these numbers you could sustain beyond the occasional personal or family use of your product or service? The business planning process can be very helpful to "accidental entrepreneurs" as it allows you to decide which ideas are best left as hobbies and which ones could provide some real cash flow.