Understand gaps and weaknesses within the plan. 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.
If an online business, you need to go into detail how you will attract customers to your website. General statements like "I will use Face Book ads and email marketing" will contribute almost nothing to helping your cause unless you have detailed statistical analysis of tests you have conducted or of another similar business you have been associated with. If you do not have any data upon which you reference your estimates, it could show lack of proper thought to the remainder of your business plan.
Start by writing a description of your business, including what stage of development it is currently in (conception, start_up, first year, mature, exit) and your plans for growth. Discuss the nature of your business, the main products and services you offer, the market for your products and services, and how and by whom the business is operated.
Who should prepare the plan? _ As a business consultant, this may sound like heresy, but I believe that any plan should be produced by the senior management of the organisation. That is not to say that the consultant does not have a role to play in its preparation. He does. Senior management should prepare the plan as they will then be able to present and discuss it, demonstrating to their audience that they fully understand their business and market. I believe that the consultant's role is to help facilitate the preparation of the plan, the consultant can help undertake the necessary research, and can cast a critical and impartial eye over the plan.