Study the Words
When one davens, he must understand what he’s saying, not merely the translation of the words. Every line is another gem, another important thought we must live with. Even the word “Hashem”, you have to study what it means. First, Hashem means the One Who has existence; another meaning is that He is the One Who causes existence. These are just general headings, but once you start learning what “Hashem” means, the next time you say it, you’ll really think about Hashem. And the same goes for the rest of davening as well. Study what the Siddur is saying, and you’ll soon begin to see what davening is.