Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, I recommend focusing on each character’s strengths. Don’t be afraid to mix up their paths to make them versatile in battles. For side quests, make sure to complete the Monster Arena challenges for great rewards. As for character builds, experiment with different abilities and stats to suit your playstyle. And don’t forget to unlock key abilities like Quick Hit and Ultima for a powerful party! Happy exploring!