There is an old but exceptionally true saying ... "Fail to Plan and you Plan to Fail" ... A Business Plan is your "roadmap" to your business direction and often the difference between a business succeeding as opposed to a business collapsing and become a statistic. You need to understand your own business inside out before trying to sell your product or service to your client. If you don't understand it yourself then you cannot expect your clients to understand your product or service or the direction your business is heading.
Eg. Working out fixed costs per product. You need to know your wholesale costs, shipping costs, tax/import duties, storage costs, etc to be able to work out how much mark up you place on each product to determine a reasonable profit margin to ensure firstly profits and secondly capital growth to allow your business to expand. This and many other factors are accomplished when you formulate your business plan.
One of the most important factors of any business plan is a SWOT (personally and also on your business and your competition as entities). A SWOT stands for Strengths, Weaknesses, Opportunities and Threats. It may sound a little strange if you have never done a SWOT analysis before, but it is a crucial factor. You need to know what your own personal strengths are that you can apply to your business (eg. Experience, ability), your weaknesses (perhaps you don't like confrontation with customers when negatives are given to you, or perhaps you dont like talking on the phone, etc), your opportunities (example of new business owners is they can operate from home based offices, keeping overheads down therefore offering lower prices than their competition) and threats (if you are a sole trader a threat could be getting sick and being unable to function in your business and service your customers, or perhaps restricted cashflow could be a threat). Every person has a different SWOT, but it is an important thing to know. And even more important to know your main competitor(s) SWOT scenario. Eg - Strengths of a competitor could be good cashflow and capital to allow mass advertising, or well branded business that is recognised by people, and their weakness could be your new business offering the same products at greatly reduced prices as your overheads do not compare with theirs therefore they cannot drop to compete with your price cuts. Etcetera, etcetera.
We have a free business plan template online that you are welcome to download (in word format) that allows you to fill in the blanks to get a basic business plan accomplished. This will at least get you started if you are a little confused on how to write or formulate one. Download it by clicking the link here - Free Business Plan
Hope this helps