Make sure that people who are in client-facing roles are putting their best face forward.
Pick the right people. Get them training. And make sure that they have an understanding of the client’s needs. A technical explanation won’t work well if the recipient does not have a technical background. A too-basic explanation will insult a technically-competent client.
Make sure that they can give good responses to questions—either they know the right answer, or they know how to get the right answer for the client in a prompt manner. Your company will lose a lot of credibility if clients are being given bad info.
Patience and positivity can go a long way in a client-facing role. Most people can be trained to competence for a role like this, but it may not be the best use of their time. Put the right people into the right roles, and you will save yourself a lot of hassle.
(image source: https://news.hometalk.com/en/memes-america-humorous?ly=native_one)