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 and match different paths to create well-rounded characters. For side quests, be sure to complete the Monster Arena battles for great rewards and the Celestial Weapons quests for ultimate weapons. As for character builds, consider specializing each character based on their unique abilities. For example, Tidus can excel in speed and agility, while Lulu can focus on magic. Happy exploring!