Know your business model before starting your plan.
Starting a business plan before you are crystal clear on your business model is a waste of time. The business plan is supposed to provide detailed procedural and financial information about how you will implement your business model in the markets you are pursuing. If you don't know the model inside out the business plan will change over and over in response to new discoveries you make about what your model really is. Make sure you are solving a problem people care about A