First, answer the question: “if someone from Mars visited your business, what would they see or sense?” This provides an objective foundation for a vision statement.
Then, based upon the understanding of where the business currently stands, a vision statement should be developed as a snapshot of where you think the business will be in three or more years time in terms of its likely physical appearance, size, activities etc. Consider its future products, markets, customers, processes, location, staffing etc.