In his introductory paragraphs to the section concerning the subject of Tefillah (prayer), Reb Chaim prefaces his remarks by examining the nature of blessings in general, their purpose, and their particular construction for the sake of fulfilling that purpose (emphases mine):
The word baruch does not mean "blessed" or "praised" (as an adjective), as most people think...
The true meaning of beracha is asking God to increase that which is being blessed as in "He will bless your bread and your water" (Ex. 23:25) and "He will bless the fruit of your womb" (Deut. 7:13)...These passages clearly denote increase; they certainly cannot be interpreted as expressions of praise and glorification.
But when we recite a beracha and "bless God", we are not speaking about God Himself. After all, God is perfect and lacks nothing; thus, "increasing" anything about Him is ridiculous.
The essence of God is completely beyond human comprehension. When we speak of God, we are referring to His attributes as they become apparent to us by the way He sustains and guides the world and His creations - with Justice, Kindness, or Mercy. That is why we describe Him as "Almighty Judge", "Merciful One", and "Compassionate One".
And so, the purpose of reciting a beracha is to increase our awareness of God in creation (first in our mind, and then in the minds and lives of as many people as we can reach). Therefore, when we bless God, we are really saying "Please increase Your presence in creation." (Sha'ar Beis, Chapter 2) *Reb Chaim elaborates further on this concept and its implications throughout the section, but this integral idea jumped off the page at me. We aren't really telling God that He is praised so much as we are asking Him to strengthen the awareness of the Divine in the world. This passage caused a paradigmatic shift in my approach to berachot by teaching me to keep this thought in mind.
* English adapted from Rabbi Avrohom Yaakov Finkel's translation Nefesh Hachaim: Rav Chaim of Volozhin's classic exploration of the fundamentals of Jewish belief (the Judaic Press).