Hey fellow Final Fantasy X explorer! When it comes to side quests, there are a few must-dos to enhance your gameplay experience.

1. **Capture Monsters**: Unlocking the Monster Arena is a fun challenge. Capture various monsters across Spira to fill it up and unlock rare items and abilities.

2. **Celestial Weapons**: Each character has a unique Celestial Weapon with powerful abilities. Completing their respective side quests to power them up is essential for end-game content.

3. **Blitzball**: While not for everyone, Blitzball can be a fun distraction. Recruit players, level them up, and compete for prizes. Plus, Wakka’s Celestial Weapon is obtained through Blitzball!

4. **Al Bhed Primers**: Finding and collecting all Al Bhed Primers unlocks the ability to decipher Al Bhed language, making your journey easier.

Remember, side quests not only offer great rewards but also add depth to the story. Happy exploring!