Hold the deck firmly with both hands.
Split the deck into two roughly equal halves.
Place the halves side by side with the inner edges facing each other.
Lift one half slightly and release cards so they interleave with the other half.
Continue interleaving until all cards are transferred.
Gather the interleaved cards back into one deck.
Square the deck by tapping the bottom edge on a flat surface.
Repeat the shuffle if desired.