Secondly, all the cards should have a square holofoil tile on the bottom right. There should be the word Yu-gi-oh and an eye in it. If the tile is placed a long way away from the side, the card is fake.

Thirdly, if the entire card is shiny, the card might be fake, but this is not definitely the case.

Fourthly, check in a yugioh magazine to see if the cards are common etc. to make sure they are real.

Finally, buy the card from reputable shops such as Argos, instead of stalls. If the deal seems to good to be true, it probably is!

Thank you for looking, I hope this guide has helped you.