Good thread, and while very in depth, I enjoyed reading selfin's response - helped me bone up on some definitions for starting the new course next year!!!
My answer is similar to Irish's.
Basic IF tracking theory - you're always on the tail of the needle. It's just that, if it's an NDB, you read the head of the needle to work out what to say. VOR or TACAN, read the tail.
I've had plenty of students who get mixed up trying to add 180 degrees to their radial and screw it up for ATC - this way you can only really screw it up if you forget what you're tracking!
Let's just avoid any further confusion or over complication by not mentioning the differences in applying magnetic variation.... though this might only be an issue for those of us who live in a country as wide as Australia!!!