The foundation AKA most important because there is no effective communication without understanding first. So ... we survey, dig deep, find whys, hows, simplify your messaging ... to come up with an elegant high level idea.
Don't worry about length. Write out your story in excruciating detail. Keep on re-writing it unti it flows like milk and honey. You cannot write too much at this stage, so let your hands go :)
Use visuals to simply chunks of text. Find shortcuts to quicker paths of understanding. This is the easiest part of the process if you don't hold back on the first 2 steps. (or if you hire us)