Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, focus on unlocking key abilities like Quick Hit for Tidus and Holy for Yuna early on. For side quests, don’t miss out on the Celestial Weapons and the Monster Arena for some great challenges and rewards. As for character builds, consider customizing each character’s path on the sphere grid to maximize their strengths – like giving Auron more strength nodes and Lulu more magic nodes. Happy exploring!