To do a two hand fan, hold the deck with your left hand in the downer position, thumb facing you. Use your thumb and push the side of the deck . Use the thumb and the strength of the left hand's grip to adjust how the fan turns out.
To do a double fan, in-jog the top half pile and hold that with the right hand, hold the other with the left handin the on hand fan position, no do a one hand fan in each hand.
Hold the deck with four fingers in front and thumb in back. If using right hand, point the deck left etc. Use your thumb to push the cards in the opposite direction to make a fan.
To Spread a deck of cards, hold the longer ends with the right thumb and middle finger, and spread it on a table, adjust the speed it drops on the table with the index finger. hold up the left side's cards and push it up to the right side creating a wave like thing. You could also hold on it with another card, pushing it back and forth, or you could use another card and split it into TWO waves.