Like making fire by rolling two sticks together, you roll the penis between your hands.
Get the guy excited, giving him a hard on.|
Put lubricant on your hands.
Place your hand each at one side of the penis, your little fingers at the side of his belly.
Move your hands in opposite directions, like you do when you are trying to make a roll out of a piece of clay.
Get into a rhythm, not disrupting it, and keep the way you move your hands steady.
Change the spot you are stimulating: go from the base to the top and back again. If you concentrate on the tip too much it may become numb, which doesn’t help to get the guy excited.