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 fill in missed nodes for stats and abilities. For side quests, make sure to complete the Monster Arena challenges for great rewards and to capture all the monsters in each area. As for character builds, tailor each one to fit your playstyle – whether you prefer Tidus as a speedy attacker or Yuna as a powerful mage. Experiment and have fun customizing your party’s strengths!