I think that Gratitude is perhaps one of the most excellent forms of “prayer.”
It combines a kind of inherent humility and recognition that "I" am not in control of The Whole Thing – whatever your philosophy or religion says THAT is. And it is truly open-hearted, if it is real.
And it is a kind of active “Thank you,”, which seems like the best stance one can take toward the Universe, whenever possible.
I wrote something long ago about gratitude being the first step into Love, and I think it is.