(This is a very abridged version of the answer) No one should enjoy having these types of scenarios. However, it is important that you show up and do not sweep items that need to be addressed under the rug, so to speak. One should always gather as much information as possible prior and time willing. Always be objective, addressing unwanted actions or behaviors rather than your personal feelings. If the conversation deals with a termination, the one being terminated should not be surprised of the outcome. There should have been enough discussions and mentoring opportunities to correct behaviors (with everything documented) prior to a termination.