At the blog Ordinary Human Language, Brian Crane has put together a series of tutorials on how to export from Tinderbox. As he says about his approach:
… what I’ll try to do is show how working backwards from the desired output rather than forward from a note is a useful (and manageable) way to think about export. In my opinion, working this way resolves a lot of the difficulty I initially experienced.
I always found exporting from earlier versions of Tinderbox to be somewhat baffling. Tinderbox 6, however, made it a little easier, though I confess that I do not do a lot of exporting from Tinderbox.