Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, make sure to focus on unlocking key abilities for each character first before branching out to other areas. Utilize the expert sphere grid for more flexibility in customizing your character builds.

For side quests, don’t miss out on the Celestial Weapons and the Monster Arena challenges for valuable rewards and ultimate boss battles. Also, be on the lookout for Al Bhed Primers scattered throughout Spira for language decryption.

As for character builds, consider specializing each character in specific roles like Tidus for speed and agility, Yuna for white magic and summoning, and Auron for physical strength. Experiment with different abilities and mix and match to find the best synergy for your party. Happy exploring!