Hi Busby - here's a thread on what people do before reading:
http://www.tarotforum.net/showthread.php?t=242721
How detailed my ritual is depends on my mood.
To Start -
Some days I may just sit down, take a deep breath and deal... then tidy up and get on with life.
On others - I'll set the scene with cloth and crystals, including my turquoise statuette of
Hotei (the laughing Buddha - patron of diviners) and a clear quartz for "clearer, stronger, channels".
Then sit down and clear my head with some deep breathing, and recite my little Tarot Chant:
"Sun, Moon, Stars, Infinity
I am that of which I Seek
Lord, Lady, Sacred Androgyne
I am all that which I meet
Powered by the Seven Spheres
I grow in strength unseared
Spirits speak!
Luce Verita e Pace" (see post 4 on the above link for explanation of the meaning).
Then I begin reading.
To Finish -
I'll shuffle the deck thoroughly, tap it on the desk and say "clean up please!"
and tidy everything away with gratitude. Then... I may ring a tuning fork or bell (or clap) - to "clear the room".