Yes, you actually CAN use your Yu-Gi-Oh! TCG cards to tell fortunes!! I've tried it! These cards are especially suited for tarot readings because they come in so many different combinations that a normal tarot deck can't compare with. I suggest you use your own playing deck that you have either built yourself or completely modified from a starter deck. Believe it or not, the 'Heart of the Cards' (in a way) comes into play here. By choosing your own cards to put into a deck, you become more in touch with the cards in that deck than the ones that are not. If you have several decks, use your favorite one.
Tarot spreads
You can use any normal tarot spread, or you can use this one I've designed myself.
Card 1: the querent or subject-- This card tells you about the person asking the question. If you're doing a tarot reading for yourself, this card represents you.
Card 2: faults and/or weaknesses-- This card represents the traits (of the querent) that will hinder the querent in the question being asked.
Card 3: Strengths/talents-- I put this card after faults for the simple reason the people need to recognize their faults and not focus too much on their strengths. A truly successful person knows their limitations. But, back to tarot... This card represents traits that will help the querent in the question being asked.
Card 4: Past-- This card shows past events that shape the outcome of the results.
Card 5: Current situation-- This card shows current goings-on that shape the outcome of the results.
Card 6: Suggested course of action-- I think this one's fairly self-explanatory.
Cards 7, 8, and 9: Obstacles-- these three cards represent your three biggest obstacles in reaching the outcome.
Card 10: Final result-- As with card 6, I think this is self-explanatory.
I would like to say that the final result is one of many, MANY possible results; it may or may not be to your liking, and it may or may not end up being true. Tarot shows one path out of many that are possible, so if you keep that in mind and try to keep the reading fun and light-hearted, tarot with your Yu-Gi-Oh! TCG cards can become a great hobby for you and your friends.