Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, don’t be afraid to mix things up and experiment with different paths for your characters. It can be beneficial to focus on each character’s strengths, but also consider branching out to learn new abilities.

For side quests, make sure to complete the Monster Arena challenges for some great rewards and tough battles. Also, don’t forget about the Celestial weapons and Aeons quests for some powerful upgrades.

When it comes to character builds, think about the roles you want each character to play in your party. Tidus and Wakka can excel as physical attackers, while Yuna and Lulu are great for magic users. Don’t neglect the support abilities either, as they can make a huge difference in tough battles.

Happy exploring! Let me know if you have any specific questions or need more tips.