Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, I recommend focusing on each character’s strengths. For example, Tidus excels in agility and speed, so prioritize nodes that enhance those attributes. For side quests, don’t miss out on the Celestial Weapons and capturing fiends for the Monster Arena. As for character builds, experiment with mixing different abilities to create versatile party members. And don’t forget to customize your sphere grid with key abilities like Quick Hit and Doublecast for a powerful team! Happy adventuring!