Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, I recommend focusing on unlocking key abilities for each character first before branching out. Don’t be afraid to backtrack to grab important nodes. For side quests, make sure to visit the Monster Arena for some epic battles and rewards. As for character builds, remember to specialize each character based on their strengths. Tidus for speed and agility, Auron for raw power, and Yuna for white magic. Happy exploring!