How to develop mision and vision statement?

Mission and vision statements are short, motivating statements that plainly explain an organization's goals and beliefs.

What is the difference between Vision Statement and Mission Statement?
The main distinction between them is that the mission statement defines what your organization does, while the vision statement describes what the organization hopes to accomplish in the future.

How to Write Your Vision Statement
Your vision statement describes where your organisation is going - it expresses your ambitions. 
It is forward-looking and outlines how you assist people, the value you provide to the world and what you hope to accomplish as an organization.
A vision statement might be as short as one line or as extensive as a few paragraphs and should be uplifting, motivational and inspiring.

Write it in a simple, common language that you, your target audience, and your staff can understand.
Use short words and phrases. The shorter the better.
Keep your wording as concrete as possible. Long and unclear phrases are difficult to understand and might lead to misunderstanding.
Concentrate on what your organization does for others, such as how you assist your target audience and motivate staff. 

Examples: Vision Statements
Save the Children (nonprofit) – “A world in which every child attains the right to survival, protection, development and participation.”

The Task Force for Global Health (nonprofit) – “A world free of debilitating diseases where all people are protected by strong public health systems.”

Planned Parenthood of New York City (nonprofit) – “Building a world where all communities have full access to innovative, high-quality, affordable, evidence-based sexual and reproductive health services, which will always include abortion, whenever, wherever, and however they are needed.”

Bulldog Athletics (University of Redlands) – “With excellent coaching, teaching, and mentorship, Bulldog Athletics promotes the holistic development of the student-athlete through competition and sport. We foster relationships to promote connectivity, belonging, and acceptance within the Bulldog family, which leads to success in athletics, in the classroom, and throughout life.”
Sports Prep (athlete training) – “Our vision is to set the standard of excellence for sports by providing first-class programs, professional instruction, and life skills. These sports opportunities and programs will contribute in a unique way to their development as athletes and citizens for the future.”
IKEA - “Our vision is to create a better everyday life for many people.” That's inspiring, concise, and to the point. It establishes the company's tone and makes it apparent that they aim to provide low-cost, high-quality furnishings that fit everyone's lifestyle.
Nike - “Bring inspiration and innovation to every athlete* in the world. (*If you have a body, you are an athlete.)” Take note of how they treat everyone as an athlete. It's both creative and welcoming.
Amazon - “We strive to offer our customers the lowest possible prices, the best available selection and the utmost convenience.”
Google - “To provide access to the world’s information in one click”.
Tesla - “To create the most compelling car company of the 21st century by driving the world’s transition to electric vehicles.”
Facebook - “People use Facebook to stay connected with friends and family, to discover what’s going on in the world and to share and express what matters to them.”

How to Write Your Mission Statement

A mission statement is a few brief phrases or paragraphs that describe what your company does to accomplish its vision statement. 
Consider why you started your organisation in the first place.  
A mission statement provides perfect clarity behind the “what,” the “who,” and the “why,” of your organisation. 

Three things are clarified by a powerful mission statement:
why your organization exists
who is it for
how it serves them 

The aim is for readers to understand the value your work provides to the world or to their lives, feel motivated to join your mission,
confident that your goal is realistic, and be crystal clear about the nature of your organization.

Use present tense when you write your mission statement to describe why your organization exists.
Mission statements should be short, clear and powerful.
The majority of mission statements are one to three sentences long, within 100 words tops.
*Keep in mind that the finest mission statements are usually just one sentence long. 

Examples: Mission Statements
Starbucks - “To inspire and nurture the human spirit—one person, one cup, and one neighbourhood at a time.”
LinkedIn - “To connect the world’s professionals to make them more productive and successful.”
Google - “Organize the world’s information and make it universally accessible and useful.”
Charity water (nonprofit): "Bringing clean and safe drinking water to people in developing countries."
Make a Wish America (nonprofit): "Together, we create life-changing wishes for children with critical illnesses."
Fellowship of Christian Athletes (nonprofit): "To lead every coach and athlete into a growing relationship with Jesus Christ and His church.

National Alliance to End Homelessness (nonprofit): The Alliance is a nonpartisan, nonprofit organization committed to preventing and ending homelessness in the United States