JSF pages are hard to debug, so adding a ui:debug in the main template. The idea (as explained on http://stackoverflow.com/questions/4049531/uidebug-tag-not-working-in-facelets-jsf-2-0) is to add a ui:debug and some config in web.xml so only the debugging shows up in development.
So in the pageTemplate.xhtml we would add :
And in the web.xml :
Then, once in any page, you just need to press CTRL+ SHIFT + D