Perhaps the single best technique for understanding the views and feelings of others regarding messaging is to use focus groups, which are, in essence, group exercises dedicated to teaching empathy. Focus groups, at least those that are conducted by skilled professionals, are effective in helping people acquire empathy because the conversation often snowballs to allow participants to see the perspectives of others.
The goal is never to reach a consensus but to simply experience other people’s feelings and understand them. This allows you to learn how to engage the intended audience and create a successful relationship: the point of messaging.