Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, focus on unlocking nodes that boost your characters’ strengths early on. Prioritize HP, MP, and key abilities like Doublecast or Quick Hit. Don’t be afraid to backtrack to grab missed nodes or take on the tougher battles for more sphere levels.

For side quests, make sure to complete the Monster Arena challenges for rare items and AP. The Celestial Weapons quests are also a must for ultimate gear. And don’t forget about capturing fiends for the monster arena and unlocking hidden Aeons like Yojimbo and Anima.

As for character builds, tailor each character to their strengths. Tidus for speed and agility, Auron for raw power, and Yuna for white magic and summoning. Experiment with different paths on the sphere grid to create a well-rounded team that can handle any challenge that comes your way. Happy exploring!