The thing that popped into my mind is an intimate VO recorded on a large diaphragm condenser. If the talent has never done voice-over work and has problems with being too loud or projecting, tell the talent to get close to the mic (about 2 or 3 inches) and speak to it as if he's talking into someone's ear (like as if the mic is the person's ear).
Leave it relatively dry and add slightly more reverb to the foley and things happening in the environment while he is narrating to separate the "head voice" from the rest of the environment (it's all about contrast).
I've done this with great success in the films I've worked on that needed this treatment.
There are also countless examples of this dry treatment in great films:
The Thin Red Line "I shot a man" sequence
etc. etc. etc.
WARNING: Closer mics mean louder mouth noise and clicks. Be ready to spend a while editing those out.