When it comes to writing a business plan!
"By its very definition, a business plan is a plan for the business, clarifying why it exists, who it exists for, what products and services it provides, who the client is, how it intends to develop and deliver these products and services, and where it is headed," Rebecca Jones wrote in Information Outlook.

Conceptualize a Business plan
Think about what sorts of gaps or bottlenecks are there in various job, businesses, workflows, etc, then think about how to solve them. Think about any product/service your company can provide which can make your customer’s life easier and may be quicker.The savings the buyer would incur in terms of money, time or effort is the sales hook.

It may be an existing service or product and you may want to do it because you like it. These are just suggestive lines of thinking. Feel free to have any feasible idea on a different line and build on it.

The process of preparing a business plan serves as a road map to the future by making entrepreneurs and business owners think through their strategies, evaluate their basic business concepts, recognize their business's limitations, and avoid a variety of mistakes.

When it comes to writing actually!
You will then need to structure your thought and present in a methodical fashion. The business plan can be broken into the small pieces in the following manner:

• Business Idea: The business idea description includes not only a profile of the company, but also a picture of the industry in which the company operates. Every business operates within a specific context that affects its growth potential. The description of a company's operating environment may cover new products and developments in the industry, trends and outlook for the industry, and overall economic trends.

  The intent of the company profile, meanwhile, is to provide readers with a description of unique features that give the company an edge in the environment in which it competes. Other topics covered include operational procedures and research and development.
  

  • Reason for selecting the business: It needs to be brought to notice if it is a new never-implemented-before idea or an existing solution but the market is so big that you can have your pie of the cake too.
  • Long term Strategy/Sustainability: The strategy will reveal how specific products and services will be developed, while descriptions of pertinent contracts and agreements should also be mentioned.
  • Business Environment: For ex. The movement in dollar affects the bottom line in the IT industry.
  
  
• Estimate Market Potential:
  
  
  • Market size: A thorough market analysis serves as the basis for a company's sales and marketing plans. The analysis generally covers the company's competition, customers, products, and market acceptance.
  • Customer Segment: This section of the business plan highlights how the company's products or services satisfy previously unfulfilled market needs. It also includes evidence of market acceptance of the company's unique products or services.
  • Competitor Analysis: The competitive analysis details the competition's strengths and weaknesses, providing a basis for discovering market opportunities.
  
  
• Breakeven: This section covers the financing and cash flow requirements implicit in other areas of the business plan. If the business plan is written for investors or lenders, the amount of financing required may be included here or in a separate section.
  
  
  
  • Time frame: It will talk about your plan and major milestones that you foresee.
  • Expenditure: It contains projections of income, expenses, and cash flow, as well as descriptions of budgeting and financial controls. Financial projections must be supported by verifiable facts, such as sales figures or market research.
  • Revenue: Monthly figures are generally given for the first two years, followed by annual figures for the next three to eight years.
  
  
• Major Challenges: This section defines problems and challenges that the company may face and outlines contingency plans for overcoming obstacles that might arise. Specific topics that may be explored are competitive responses, areas of weakness or vulnerability, legal constraints, staffing, and continuity of leadership.
  
  
  
  • Short term Challenges: This will talk about challenges you can see in the next couple of years.
  • Long term challenges: This will look at a longer period like 3-5 years discussing broader challenges the company is likely to face.

The business case should be supported by secondary research and the data should be represented properly with graphs/pie-charts where ever necessary. Also provide us with relevant sources for the secondary research.

Done Writing!
Now what! Review it for the following things:

• Check for glamour in your business plan
  While you might have fantastic computer skills and a creative flair to beat all creative flair, it won't improve your business plans. Keep the artwork, the fancy fonts, the pretty borders for your menus, brochures, advertising, signage, etc. instead. A business plan must be clean, crisp, and easy to read by a range of persons with varying levels of interest in and understanding of your business. Distractions such as artwork can lead to questioning the seriousness of your plan, and whether or not you're making a deliberate attempt to distract from not having adequate information available in the plan.


• Check for business jargon or tech-speak
  The big words sound good but they don't always mean the same thing to you and the reader. And as soon as you get technical in a field that isn't your expertise, you risk losing the reader and making errors. Stick to the facts and to what you know best. Use plain English, simple words, and get to the point.


• There should be no abbreviations and your own shortcuts
  unless these are clearly explained at the beginning of the business plan. People who haven't a clue about your business will be reading this document; don't assume they know your "in-speak".


• It should be to the point
  Avoid lengthy descriptions or rambling ideas. Make your point quickly each time and use engaging language that a reader can get through easily. Break down difficult concepts into simple language and use diagrams, charts, etc., if these help to simplify.


• Proofread
  Spelling areas, mistakes with names, figures, etc., and grammar faux pas are unforgivable and reduce the sense of confidence in your venture. If you're not confident with your writing skills, enlist the help of someone who is good at this and have them check for errors. Get someone who is good with numbers to check your figures; and double check them too.