Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, I recommend focusing on each character’s strengths. Start by unlocking key abilities like Haste and Curaga early on to make battles easier. For side quests, don’t miss out on the Celestial Weapons—each character has a powerful weapon waiting to be obtained by completing specific challenges. And for character builds, consider customizing your sphere grid to complement each character’s unique skills. Experiment with different paths to create a well-balanced team capable of taking on any challenge in Spira! Good luck on your journey!