Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, my tip is to focus on unlocking character’s key abilities first before branching out. This way, you can maximize their strengths early on. Don’t be afraid to backtrack to grab important nodes like HP, MP, and stat boosts.

For side quests, be sure to complete the Monster Arena challenges for some great rewards and tough battles. Also, don’t forget about the Celestial Weapons quest for ultimate weapons and the optional Aeons like Yojimbo and Anima.

When building characters, consider their unique strengths. For example, Tidus is great for speed and agility, so focus on agility nodes for him. Auron is a powerhouse, so prioritize strength and HP for him. Mixing and matching abilities from different paths can create versatile builds too. Happy exploring!