Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, focus on unlocking key abilities for each character first before branching out. Use Spheres strategically to boost stats based on each character’s role. For side quests, don’t miss out on the Celestial Weapons and Aeons like Yojimbo and Anima. They can be powerful additions to your arsenal. Lastly, experiment with different character builds to fit your playstyle. Mix and match abilities to create a well-rounded party for any situation. Happy exploring!