DF cards are among the most useful items a card magician can have. DFs can be used visibly (where the spec is actually shown the DF) or invisibly (where the spec does not even know a DF is in play). Here are some effects that can be done with this gimmick.
Anniversary Waltz– One of the strongest and most sentimental effects a magician can do. The Magi approaches a married couple. The Magi then has each of them select and sign a card. These cards are lost into different places of the deck. But yet, the magi spreads through the deck and they are right next to each other. As a finale, the magi has the couple sandwich their cards together. And when the specs lift up their hands, both signed cards have fused together. Such a beautiful routine.
True Love– Essentially the same plot as Anniversary Waltz, however, it is extremely simplified. This is basically the Street Magic version of Anniversary waltz. Its quick and direct, and some phases of the original routine have been removed and altered.
Astral Projection– A great mentalistm routine. This is an effect that uses a DF invisibly. Basically, a thought of card vanishes from one packet of half of a deck, to the other. I really like this effect. Its by Jay Sankey.
Strange Travelers– Along the same lines as Astral Projection, but much more “Street”. This has some other added elements such as counting the cards. Its a great packet trick, and has been performed by David Blaine.This is the single effect that convinced networks to do his first Tv special.
McDonalds Aces– A classic routine utilizing the four aces. Its simply beautiful. It was performed by Criss Angel on national television.
Performances of all of these can be found on www.youtube.com.