In coaching sessions when clients are focused on how to handle a particular conversation, it is sometimes helpful to role play the conversation. Start with the coach being the client and the client being the other person. This way the coach is modeling language and interaction while at the same time learning about the anticipated behavior of the other person. Then trade places with the coach, being the other person and the client being them self. This way the client immediately practices with some of the ideas learned from the coach role playing, and also gains a comfort level in how they handle it.
For example, when a client is scheduled to meet with their boss for a performance review and to discuss a promotion, role playing the conversation helps the client prepare. Start with the client in the role of their boss and the coach in the role of the client. After a few practice conversations, trade places so the client is them self and the coach is their boss. Practice several times again.
After the role play, asked the client what insights they gained, what possibilities they want to be ready for, and what specific language and other techniques they want to use in the meeting. Then ask them to describe a successful meeting occurring as if they are a fly on the wall observing it. Then work with them to plan their preparation and their confidence.