One of the first things to consider when working with metadata is documentation.
A simple README file is one of the best ways to help you document, work with, and get to know your metadata. Most importantly though it will help you keep track of changes that you make to a file, questions that you have, problems that you encounter, and discoveries that you make. It can also be used to document how you use a file with a another tool or software.
Data Exploration - Tableau
Tableau - https://www.tableau.com/academic/students - is a powerful platform that can be used for visualizing data. We have used it with many of our collections. One of the most interesting ways to use Tableau is as an image viewer. If you have a field with with an image URL you can create different types of viewers that can instantly give access to large collections. For example, USC's Wayne Thom collection is approximately 10,000 images. Using Tableau we were able to offer a one page snapshot view of every single image, grouped by category, represented as small boxes. When the box is hovered over it reveals the image with some corresponding metadata.