As a Reformer focused on the literal sense of Scripture and employing good historical and grammatical exegetical tools, Calvin could be expected to "de-mysticize" Scripture in a way, but I am struck by how he began interpreting Scripture by relying on the Holy Spirit to speak through the words of Scripture before he began the hard work of studying the text. A Reformed hermeneutic, or any good reading of Scripture for that matter, must begin with reliance on the Holy Spirit. Because the Holy Spirit speaks in all of Scripture, the entire narrative and the words of other passages must inform how we understand the passage we have selected to study.
When the Holy Spirit speaks in Scripture, he does so to reveal Christ to us. Any good reading of Scripture must point the reader to Christ. Sadly, Calvin himself shied away from this more than his descendants, out of fear of over-allegorizing the text.
Because Scripture points us to the love of Christ, love should play an essential role in our reading of it. It ought to produce love for God and love for others. Sadly, in more recent years, the Reformed community has not always been known for being loving towards other Christians who notice different things in the text from them.
Our reading of Scripture must also conform to the rule of faith. While we do not read Scripture merely to provide prooftexts, what we learn in Scripture should conform to the way the church has understood the Gospel as summarized in the Apostles' and Nicene Creed and must not deviate. Underneath of the creeds, any time we wish to deviate from the traditional exposition of a passage, it must only be done after careful and prayerful study of the text. We cannot be quick to throw out the readings of our spiritual ancestors and must be certain when we respectfully go a different route.
While the Holy Spirit speaks through the text of Scripture, he does so in a way that takes into account the culture, history, and times the passage was originally born in. To hear the Holy Spirit speak faithfully, we must do the hard work of understanding the historical circumstances and literary forms used in a passage. Once we have worked our way into the original context of the passage, we will have removed our barriers to understanding what the Spirit has to say.
Finally, we must be humble in our reading of Scripture, recognizing that we are fallible, that others will read it better than we or will notice different valuable insights we missed, and that we will have to correct our understanding in conformity with Scripture. In reading God's Word, we must always be willing to be reformed again and again by God's Word.