Mary of Bethany had the right idea...

From a great article on what it means to be a mystic (all emphasis mine) :

What makes a mystic, well, “mystical”? Mystic and related words come from the Greek language — from the same word which gives us mystery and even sacraments. But the Greek root word, mueo, also gives us the English word mute. So a mystic is someone who enters the mystery of God. And a mystic also, and therefore, is someone whose spirituality is muted (in other words, profoundly silent) — which is to say it cannot even be put into words. It’s the silence of a monastery, understood not merely as the absence of sound (or thoughts, or words), but as an opening that allows us to discern the quiet presence of God. 

A mystic, in the broadest and m[o]st humble sense of the word, is simply someone whose relationship with God is primarily contemplative. Someone who prays, and who prays silently, opening the heart to the presence of God, which cannot ever be fully put into words.

 The author wisely comments:

Our job, in our time, is not merely to try to replicate the spirituality of the great mystics of the past, but to immerse ourselves in their wisdom to find inspiration for God to lead us into our unique expression of intimate union with Him.  

Let it be done unto me!

Christ in the House of Martha and Mary - Henryk Siemiradzki (1886)