Titlecase Indesign Script
I can’t take credit for the script; I used David Gouch’s Titlecase script and added in Mozilla’s Array.prototype.map() polyfill code.
I worked at a newspaper for a while which insisted on New York Times style titles, which is what Titlecase tries to do. Almost none of the submitted headlines actually used Titlecase, so after a while my creative laziness kicked in and insisted on a more automated solution.
Extract the file to your InDesign User scripts folder; to use it, highlight the title you want to run it on, open up the Scripts panel, and double-click on To Title Case.