Narrow down what makes you different - Differentiate yourself from other businesses in your space by considering what sets your business/offering apart.
Keep it short - Business plans should be short and concise. Too much detail isn't helpful in a business plan and will only distract and confuse stakeholders. Instead, know these details, but keep them stored elsewhere.
Stay flexible - Your business plan can and should evolve as you go. It's a living, breathing document and should be treated as such.Narrow down what makes you different.
Before you start whipping up a business plan, think carefully about what makes your business unique first. If you're planning to start a new athletic clothing business, for example, then you'll need to differentiate yourself from the numerous other athletic clothing brands out there.
Company Description
Next, you'll have your company description. Here's where you have the chance to give a summary of what your company does, your mission statement, business structure and business owner details, location details, the marketplace needs that your business is trying to meet, and how your products or services actually meet those needs.

Example of a "Company Summary" section (from Bplans):
NALB Creative Center is a startup, to go into business in the summer of this year. We will offer a large variety of art and craft supplies, focusing on those items that are currently unavailable on this island. The Internet will continue to be a competitor, as artists use websites to buy familiar products. We will stock products that artists don't necessarily have experience with. We will maintain our price comparisons to include those available online.

We will offer classes in the use of new materials and techniques.

We will build an Artist's Oasis tour program. We will book local Bed and Breakfasts; provide maps and guides for appropriate plein-air sites; rent easels and materials; sell paint and other supplies and ship completed work to the clients when dry.

We will expand the store into an art center including: A fine art gallery, offering original art at, or near, wholesale prices; Musical instruments/studio space; Classrooms for art/music lessons; Art/Music books; Live music/coffee bar; Do-it-Yourself crafts such as specialty T-Shirts, signs, cards, ceramics for the tourist trade.

Step 3. Market Analysis
One of the first questions to ask yourself when you're testing your business idea is whether it has a place in the market. The market will ultimately dictate how successful your business will be. What's your target market, and why would they be interested in buying from you?

Get specific here. For example, if you're selling bedding, you can't just include everyone who sleeps in a bed in your target market. You need to target a smaller group of customers first, like teenagers from middle-income families.

From there, you might answer questions like: How many teenagers from middle-income families are currently in your country? What bedding do they typically need? Is the market growing or stagnant?

Include both an analysis of research that others have done, as well as primary research that you've collected yourself -- whether by customer surveys, interviews, or other methods.
For more details you can consult me