I’m a huge fan of Data Studio, a free solution from Google for reporting. It’s fairly easy to get started since there are templates available that were created by other users.
Once you become familiar with the basics, there are a number of advanced features that allow you to take it to the next level. One of these features is calculated metrics which I discuss on the Supermetrics blog. Read the full post here: https://supermetrics.com/blog/gds-tips-reports/