Dash off of the top waterfall basin and then jump to get piece. Pressing and together can help get Sora into a dash-jump. Can be difficult and may require time and patience to carefully collect the piece due to difficulty.
#18
The King's Den
Jump off of the small rock.
#30
Elephant Graveyard
Dash off of the big ledge in the middle. Can be difficult.
#42
Elephant Graveyard
In the small alcove.
#47
Jungle
Jump off the ledge.
#48
Gnu Valley
Under the tree near the entrance to the Wastelands.