Cắt một lỗ nhìn trộm trên hộp đựng bộ bài. Yêu cầu một khán giả chọn một lá bài. Làm động tác như thể bạn đang đọc ý nghĩ của khán giả tình nguyện. Xác nhận lại bằng cách cho khán giả xem lá bài.

I'm interested in that, but I only have a few mins. Can you give me at most the first 500 characters of a detailed explanation in English about that?
You just need a standard deck of cards that comes in a cardboard box. Remove the cards from the box and use a scissors to snip a small hole in one of the corners of the back of the box. Put the cards back in the box and take a look at the hole. You should be able to see the upper corner of the last card in the deck, revealing which card it is.  Come to your show with the card box already prepared. Keep the side with the hole away from the audience as you prepare to perform the trick. If you can