Basically what I do is, I start off with my "ritual" if you want to call it that where I first do some breathing exercises that I learnt on my Master Del Pe Healing course. This is followed by an invocation of my Guides, Angels, Faeries and all other Beings of Light that accompany me on my journey.
I then clear the room by drawing the Reiki Power Symbol three times in each corner. Finally I build an energy bubble through my hands, big enough to house me while I sit on my meditation chair, and I place the bubble on the chair.
I take my seat, shuffle the tarot deck and pick the topmost card and study it intensely by scanning it from the top left corner to top right, zig zagging and scanning a centimetre at a time.
When done, I put the deck down, close my eyes and slow my breathing. In my mind's eye I start rebuilding the card as accurately as I can in more or less the same way as I scanned it. When I reach the bottom of the card, I rescan backwards, but this time DECONSTRUCTING the card, i.e. erasing it. Once I reach the top... NOTHING! Focus on total emptiness, silence and quiet.
Now, here is where I started adding my own flavour: you are supposed to NOT focus, NOT think and NOT try anything. Just BE. To do that is difficult, but not impossible. Be attentive to your body, the back of your eyelids and the zing in your years. Try and keep it up for as long as your mind is able to.
When you are no longer able to hold it, take a deep breath, rub your face gently and your legs. Ground, and open your eyes.
Keep practicing. Don't give up. Some days you'll have strange experiences, and others you'll just come out of it with peace, calm and quite.