Scissors
I have been trying to get Hadley to use scissors properly for a long time but she hasn't has the strength to open them with just one hand so it was usually an assisted task.
However, in the last week she has been working really hard at this new skill. While her accuracy still needs some work, she does cut approximately where she intends to using just one hand with the thumb in the thumb hole and the other fingers in the proper location. She also knows how to properly hold scissors when she is walking which is also REALLY important.