Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, focus on unlocking key abilities for your characters first before branching out. Don’t be afraid to backtrack to grab missed nodes for more stat boosts. For side quests, make sure to complete the Monster Arena challenges for valuable rewards and unlock ultimate weapons. When it comes to character builds, experiment with different paths on the sphere grid to customize each character to your playstyle. And don’t forget to mix and match abilities to create powerful combinations in battle! Happy exploring!