Hey sleeping cat,
Welcome to AT! I don't make a big deal out of the whole "ritual for reading" thing. I was raised Catholic, but I don't identify myself as one; I don't agree with organized religion, at all...I have faith, and tons of spirituality, so I guess I have sort of forged my own path. But that's another story.
Just wanted to tell you where I'm coming from.
Basically, when I feel like doing a reading, I sit down with my cards, quiet my mind/mediate for a bit, then ask my guides and higher self to protect me and help me interpret the cards, while keeping in mind that I serve the querent with love. Once I feel like I have established a "connection," I envision a white/golden light coming from spirit, the energy of the "connection," as I see it, and then I take that light into my third eye and course it down my arms into the cards until I feel the energy charging the cards. And then I know it's time to shuffle. Sounds weird, I know. But it seems to work for me...I just took bits and pieces of things I've heard and some of my own ideas to make up something that works. So have fun experimenting!