Firstly, knowing what is driving the account is fundamental in making sure everything that follows will resonate with the prospect or client. This means getting into the 'nitty gritty' of what makes this customer tick, and it will have to go down to the people profile.
Personas are a great way of understanding what content will work and what comms channels will be the most effective. If you are not sure how to start, then try it out with colleagues. In the past as head of marketing I made one based on my counterparts in sales, it was an excellent exercise.
I got to learn more about the people I worked with, some things made us closer, as I found out more about their background and aspirations. It helped a great deal in our relationships and communication. It was a perfect way to start, I was able to prove that ABM was effective and also to enable us to work together on the same goals.
We could then start to build a better ABM program between us, and build personas that really reflected who we were dealing with to create a more comprehensive and customer focused communication.