I have a question in mind when I get the cards out. I focus on that question while I shuffle. I know we're ready when I feel energy between my hands and the cards. It feels a bit like "charging" an intuitive battery. I also shift my mental energy from daily tasks into a more reflective, relaxed and quiet state.
Sometimes the question changes or I find I'm all thumbs while shuffling. So I stop, focus on the new question or edit the first one and begin shuffling again.
I really only read for myself but if I am going to help my sister read from my deck, I will shuffle a couple times to "clear" the deck and picture wiping them blank. Then she shuffles however she likes.
I've used a friend's Motherpeace deck in the past. The thing I remember most about them was the way I could shuffle them by spreading them all out and moving them around in circles. There was something very pleasing about the very energetic shuffling that mirrored the shape of the cards.
