Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, focus on unlocking key abilities and stats for each character first before branching out. Don’t be afraid to backtrack to grab missed nodes or farm spheres for customization.

For side quests, make sure to tackle the monster arena for rare loot and ultimate challenges. Don’t forget about the celestial weapons and aeons for extra power. And if you’re feeling adventurous, dive into the dark aeons and Penance for the ultimate tests of skill.

As for character builds, experiment with different paths on the sphere grid to suit your playstyle. Mix and match abilities to create versatile characters, like giving Tidus both physical and support skills. And don’t underestimate the power of buffing your party with abilities like Hastega and Protectga.

Happy exploring, and may Yevon guide your journey on the sphere grid!