You get this Trophy for learning the Jecht Shot (completing it's mini game) on the way to Luca.
After getting Ifrit and returning to Kilika. You will be aboard the S.S. Winno. After witnessing Yuna tell off the Goers talk to her. (I recommend going below deck and saving as well) Go upstairs on top deck multiple times and ease-drop on the Wakka/Lulu conversation. (Repetably go upstairs until they stop). After this go to the lower deck (Opposite of the deck Yuna is on) and examine the Blitzball. You will start the "Jecht Shot Challenge" Simply point your stick in the direction of the words that randomly appear on the screen and press (X). You must succeed eleven times in order to learn the move.