Advice 1: Practice makes perfect. I would advise the employee to making drafts of written communications they need for their job, and then I would review and give them feedback to improve in the future. For oral communications I would assist them by role playing and allowing them to have a dry run.
Advice 2: Learn from others internally. I would cc or bcc them, or share other written communications that I have made so that they can learn from example. I would also let them sit in on certain meetings and conference calls to see how I handled such situations.
Advice 3: Learn from others externally. I would not claim to have all the answers for all people. I would encourage the new employee to seek outside information, whether it be in a book or online video, or by joining an organizations such as Toastmasters, which would allow them to practice their communications in a no pressure environment.
