We divide each project into stages, estimate how much time will be required for each stage, and based on the estimated hours, determine the price for the entire banner creation. For example, if we calculate that 10 hours are needed to develop your banner at a rate of £60 per hour, we get £600 as the final price.
It sounds simple, but it actually requires a lot of experience to create an accurate plan and provide an accurate estimate for a banner designed specifically for you and according to your requirements.