Everybody thinks they are brilliant at being an interviewer/ee, and yet most have had no training.
Be ready for the dreaded competency-based interview, which is just "give me an example of when you ...". Plan some anecdotes that might be called for with firm evidence to illustrate them.
Be ready for the person who asks all the wrong questions (or none at all) and be ready to list off the key achievements and skills that you have to offer that are relevant to the role, even without being asked directly to do so.
Bear in mind that in civilian life most people embellish their successes by 50% or more, whereas in military life one tends to undersell.