After reading a lot in the forums about how exhausting can the battles be, in terms of being the only way to gain Experience Points (or gold and items besides of chests), I thought about alternate ways to get XP.
It's very likely that the examples below have been used already.
1) Collect chests: This is simple, loot x amount of chests and get a XP bonus.
2) Puzzles: Complete the given puzzle to get XP.
3) Buy XP or levels: This may be overpowered if it is not correctly balanced, but it can be possible to get XP by using gold.
4) Battle avoided: Somehow, bypassing normal battles, being that the party is too strong and the player gets an instant victory, or interacting with the environment to defeat the enemies without needing to fight, is a good way to get XP.
5) Items that give XP: They can be very rare, and give a fair amount of XP.
But, they can be more common than you may think. I thought that, when using a food item, you keep the envelope, and by throwing it to a trash can, you get XP, or you can get a bit more when throwing the envelope to a recycle can.
6) Side quest: Rescue the kid on the cave or rebuild the bridge and gain XP for doing that.
Can you tell more ways to get Experience Points?