However, if you are reading for yourself with a tarot deck no one else has touched you might want to skip the clearing step. Some readers feel that the information in a reading is enhanced by the culmulative effects of personal energy built up over a period of time. Eventually you may begin to notice what can only be called energy-sludge on your cards. When this occurs, your intuitive understanding of the symbols may become clouded. The cards may begin to feel sluggish as you shuffle. If your readings become significantly difficult to understand, it's time to clear your cards.
Others feel that starting a reading with a clean slate is the only way to go. There is no right or wrong, so feel free to go with what feels right to you.
The method of shuffling the cards is also an individual choice. Your first thought about shuffling the Tarot may be to handle them just like playing cards, shuffling with two hands and letting the cards intermingle as they drop to the table. I don't recommend this style of shuffle. It does mix the cards well but it also tends to damage the cards by bending them in the middle with each shuffle. Tarot decks can be expensive and I don't know about you, but I'd rather spend my money on different decks rather than replacing ones I already own! Many tarot decks are larger than regular playing cards and this makes them difficult to handle with this type of shuffling.
Another way of mixing the cards is to just let them fall randomly on the table. Then with both hands simply move them all over, scrambling and mixing as you go. Pretend you're six years old and you'll do it perfectly! The more you move the cards, the better the mix. This method takes a pretty large table and can be slow, requiring several minutes of mixing before you get a sense of completion. I'm not a fan of this method; my mind tends to wander too much.
What works best for me is to square up the deck with the back of the cards to me. I hold the cards along the horizontal or long side and I randomly divide the deck between my two hands. Then I begin intermingling the cards by cutting the cards into themselves. I'll do this several times, with varying numbers of cards at a time. I usually close my eyes, focus on the issues at hand or the person that is my client as I mix and cut several times. You may prefer to hold the cards with the tops or short side and cut in that way, from top to bottom.
Until recently, I've cut right to left because I am right handed. Lately I've reversed that, moving left to right and I think I will stay with this method. I believe that my shuffling with my non-dominant hand I'm connecting more strongly with my intuition than my logical senses. If a card falls out as I'm shuffling, I set it aside and will use it as an additional card to clarify a reading.
Many tarot readers, especially beginners, prefer to not have any reversed or upside down cards in their readings. If you want to ensure all your cards stay upright, go through the deck before you shuffle and orient all the cards in the upright position. Be consistent in the up/down or right/left method as you shuffle.
As you've probably guessed, there are many ways to shuffle your cards. You're free to even invent your own! Do what is comfortable for you and leaves you with a well mixed deck.