In The "Lost Treasure" movie, how Tinkerbell solves the problem of the shattered Moonstone. She changes the scepter she made to incorporate the Moonstone shards and the Jewel she got from the mirror. When the light from the Moon hits the jewel in the center just so it reflects to all the Moonstone shards and shines even more light on the Pixie Dust than it usually would! Not to mention the Visual Effects of Awesome from seeing all the blue pixie dust rain down. I mean sure she broke the Moonstone in the first place but you have to admire her ingenuity.
In "This Secret of the Wings" movie, Tinkerbell flying through the Winter Woods, knowing her wings could break. When one of them does, she keeps quiet about it because she knows the Pixie Tree is more important. Her figuring out the fairy frost could keep plants alive and safe from the oncoming freeze was pretty smart too.