It has become very fashionable for companies of all sizes to have mission statements, and that is fine as long as it has meaning.
In forming your mission statement, consider why the company is in business, why is it in the business it is in, and what it hopes to accomplish. Then ask for input from employees, customers, and vendors.
Answer simple questions, such as “We exist to ______”, “We are committed to ______”, “We will separate ourselves from our competition by ______”, and “We will do so by ______”.
Then get feedback and revamp your statement. Once finalized, distribute it everywhere. Make sure it is not a meaningless statement. Instead, make it meaningful, unique to your organization, and make sure it has an impact on the behavior of all employees. Use it as a rule for tough decisions, use it in training, and make sure you never compromise it.
If you already have a mission statement, see how many of your employees know it, and hold a confidential poll on if it is being implemented throughout your business. If not, you need to reexamine your statement, or your operations.