I love the crowd reaction to this beautiful piece of work. One thing to note: I noticed that some people were slightly suspicious when I took the three cards out of a card wallet. One man said, "Are these special cards?"
So I changed it by doing a pre-set of inserting the three magic cards in a deck (let's say Deck A) and putting the real three cards at the bottom.
When I finished another routine using Deck B - a real deck, I put Deck B into my briefcase. Then, I would say, "How about one more routine?" When the crowd would say, "Yes," I would reach into my briefcase and bring out Deck A which contained the three magic cards. The crowd assumed it was the real deck (Deck B),
After doing the Ultimate 3 Card Monte, I collected the three magic cards and put them on the bottom of Deck A, next to the real three cards. After opening the briefcase, I put the deck into it but tossed the three magic cards away from the deck into the briefcase. If anyone wanted to examine the deck (Deck A), they would see the three real cards in there and be completely blown away.
Micheal Skinner's Ultimate 3 Card Monte on Bicycle Cards