Place water, butter, and salt in a medium saucepan and bring slowly to a simmer.
Turn off heat and add the flour all at once.
Stir vigorously with a wooden spoon until it forms a ball.
Return to medium heat to dry the paste so it will have the maximum puffing ability: turn the ball around in the pan.
Remove from heat and let cool a bit.
Turn the paste into a medium bowl or the bowl of an electric mixer fitted with a paddle and beat in the eggs, one at a time.
Load mixture into pastry bag with a round tip. (1/2 or 1-inch depending on size desired) and pipe out as required.