A Shabbos guest asked a fairly common question, "Who am I to bless G-d? How is that we give G-d blessings?"
I explained, what we say we experience. So if we say I love you to someone we are the ones who feel that love. If we say we hate someone, we are the ones who experience the hatred. So it is with blessings. When we say that "Hashem is blessed," as we do in the beginning of all the blessings, we move up in our understanding of G-d's nature. We recognize and acknowledge that Hashem is blessings. We are the ones who benefit from saying the blessings, not Hashem.
G-d wants us to experience a drop of His holiness, His blessedness. In order to do this we ourselves have to increase our experience of holiness and blessings. This is why Hashem has given us the mitzvahs to do and the blessings to say. They are for our benefit. They elevate us, not Him.