Thinking about maps and what they can add to a literary text (and often do) I came across this article collected in “Arts and Letters Daily” (which I find to be a wonderful source generally):

http://www.newyorker.com/online/blogs/books/2014/01/the-allure-of-the-map.html?mobify=0

The possibilities of students constructing maps for texts they read responds to another kind and level of engagement of which I wish, over the years, I had done much more.

And going on from there to mind-mapping as a way to connect texts and elements of texts surely could act as
another extension.  Though there are many, the following is a good site to get you started if you’ve not already done so, and it’s easy enough to substitute “essay” for “review.”

http://www.literaturereviewhq.com/how-to-mindmap-and-why-it-will-improve-you-literature-review/

And then there’s Franco Moretti’s inventive approach to mapping literary history: Graphs, Maps, Trees, a critical exploration that is quite engaging and provocative.