Begin by rotating your body about 45 degrees away from the target, so that the “backcast” area is clearly visible by turning your head slightly. Rotate your rod hand and arm so that the reel is facing upward; this will necessitate lifting your hand about as high as your face. Now make the “backcast” just as if it were a normal forward cast, but aim it high like a normal backcast would be aimed. During the Pause, rotate your arm so the reel is pointing toward the target area and lift (upward drift) the rod so it is in the correct position for making the forward cast. Then make the cast.
To false cast, aim the forward cast a bit higher than normal, rotate and lift your arm during the Pause and make another Galway “backcast.” Indeed, since the Galway allows you to easily see what is happening in both directions, it also makes for a good way to learn to false cast in a controlled manner.
As you practice Galway false casts you may also notice that your arm travels in a stretched X shape through the air. The “backcast” goes down one side of the X, while the forward cast goes down the other.
In between are the two lifts that get your hand and rod into position for the next cast. If you tilt the X to a steep up-down trajectory and then bend it in the middle so that the forward cast is flatter, you can even create another form of a Steeple Cast. I’ll leave you to play with that one.