Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, I recommend focusing on each character’s strengths. For example, Tidus excels in agility, so prioritize nodes that boost his speed.

For side quests, don’t miss out on the Celestial weapons and Aeons. They can provide a significant power boost for your party. Also, tackling the Monster Arena can be challenging but rewarding.

When it comes to character builds, consider mixing different paths on the sphere grid to create a well-rounded party. For instance, have Lulu learn some white magic to increase her utility in battles. Experiment with different combinations to find what works best for your playstyle. Good luck on your journey!