when I write (whether or not the characters are intimate) I am always trying to "get inside their heads". I do that because I'm trying to think like the character and not like me.

Does that make sense? I'm trying to have the action be as much like that of a character who has been through the background story that I invented for them, and not like me jumping into their story with a Mary Sue wish-fulfillment for me.

Is that what you're looking for?