I have created 60 tracks in a single multitrack session. I want to save each track as a separate .aiff file. What is the best, most efficient to do this?

If you highlight all 60 tracks in the session (Ctrl+A), and go to File>Export>Multitrack Mixdown>Selected Clips, a window will open up that gives you a location to store the files, the opportunity to select the format you want, and a box marked Mixdown options. If you click on any of the Change options, then Windows will open giving you the options you need. The last one is the one that sets up what you need for saving the files - so you take the check out of Mix, Select Track (which should turn a greeny colour) and then put checks in all of the track selection boxes. Hit Okay to get back to the Mixdown window, check the settings and hit Okay again.

This should  turn whatever you’ve got on each track into a single file per track, and it will do this for each track you’ve selected. Just remember to highlight all the tracks before starting on this!