Praying with a Whole Heart and a Clear Mind

Rav Yosef Karo, one of my favorite people from Toledo (Spain), wrote in the Shulchan Aruch, Orach Cha’yim (98:1) the following:

The one who prays must wholeheartedly concentrate on the meaning of the words which he utters with his lips. He must imagine that he stands in the presence of God. He should remove all other thoughts [from his mind], until his consciousness and concentration are completely absorbed with his prayer. He must imagine that if he were speaking before an earthly king, he would carefully compose his words and concentrate on them so as not to falter, all the more so  [when speaking] before the King of all kings, the "Holy One, blessed be He", who sees to the very heart of all thoughts. This was the practice of the early pious people and men of good deeds. They would meditate in solitude and concentrate on their prayers until they achieved a transcendent spiritual state wherein their soul overpowered their body, thus approaching a state of prophecy...

How do you teach this to kids?  Again, I find it interesting that meditation is a key word that is appearing in tefilla tips from Rabbis of every generation, but I am not hearing this word (nor concept) reverberating much amongst contemporary educators.