Some readers will take a card out of the deck, and set it on the table to represent the person receiving the reading. This can serve to sort of psychologically place the reading’s recipient right into the reading in a very visual way.
I don’t use significators, myself – I don’t like the idea of removing a perfectly good and information-filled card from the mix. What if the significator card you’re choosing was the one with the most critical advice to give in the context of this particular question?
But if you do like the idea of using a significator, you have to settle on which card to use. Most readers use Court Cards for this practice. If I were to use a significator to serve as my two-dimensional stand-in, I’d choose either the King or the Knight of Cups. The Suit isn’t in doubt for me: my birth-chart is riddled with Water Sign placements, and I totally identify. The only question is the one of rank. I’m hesitant to hold a coronation on my own behalf, and just proclaim myself a King, and also, the Golden Dawn’s system would have me as the Knight. Then again, just going by chronological age, I’d be…well, a very young-at-heart King.
How about you? Do you use significators? If so, which card do you choose to represent yourself?