As I'm polishing my contracted novel in preparation to send in, I'm going through the manuscript, making sure that my analogies and metaphors (two rhetorical devices) are plot and character-specific. When I say character-specific, I'm referring largely to the characters' careers, personalities, interests or hobbies that are predominant through the novel.
By definition in Websters:
Metaphor-a figure of speech in which the context demands that a word or phrase not be taken literally, as the sun is smiling; a comparison which doesn't use like or as.
Analogy-connection between things that are otherwise dissimilar;a conclusion or opinion that if two things are alike in some respects they must be alike in others.
So, for instance, if I have a character whose career is a NAVY fighter pilot, he might think or say things like: "Her words jerked him back like the arresting wire on an aircraft carrier." (an arresting wire is the cable thing that catches the jet, acting as a brake).
If I had a character whose career was a nurse, she (or he, since I love to turn stereotypes on their heads) might think or speak or relate to other characters in medical terms. Example: His smile infused her with strength.
Or if I have a character who is a teacher, she might think in teacherly terms.
If the character's favorite pasttime was fishing...(such as Joel's in A Soldier's Promise) he might introspect things like: Bradley's mouth gaped like the nine pound bass Joel hooked yesterday.
If I'd used that analogy...and fishing wasn't a vital part of the plot...it wouldn't make much sense and is a waste. Much better to use plot and character specific analogies.
Remember....the analogies normally use like, but metaphors do not.
Hope this helps.
Have fun analogizing!