Insight powers the most successful brands. Understanding your customers and what they value is the key to any successful branding project. There are many approaches to gathering useful insights in order to power your brand,the knowledge of the stakeholders involved in the business will be a starting point, however it is important that all stakeholders recognise that personal opinion, likes and dislikes do not play a part in the final direction the brand should take.
The customer is king and your brand should translate across all touchpoints your customers interact with. In order to do this it is first vital that you understand who your customers are and be realistic about this.
https://www.forbes.com/sites/forbesagencycouncil/2018/03/14/how-to-craft-the-ideal-user-persona-for-your-brand/#4602a8d76ead A useful guide to creating personas and the level of detail required.