Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, I recommend focusing on your characters’ strengths. Make sure to unlock key abilities like Quick Hit for Tidus and Doublecast for Lulu. Don’t be afraid to mix and match different paths to create versatile character builds.

For side quests, be sure to complete the Monster Arena challenges for some great rewards and tough battles. Also, don’t miss out on the Celestial Weapons and the optional Aeons like Anima and Yojimbo. They can really make a difference in tough battles.

Lastly, experiment with different character builds to find what works best for your playstyle. Whether you prefer physical attackers, magic users, or support characters, there are plenty of options to customize your party. Happy exploring!