When Lily says, 'Oh my gosh! Is that Orlando Bloom?" the man that just walked by, he goes to the left, but when Lily and Hannah walk into the place, they go to the right.
When Miley is Hannah and with her vocal coach, her wig changes from behind her right shoulder to in front of it and back again between shots.
When Lilly asks Miley what the noise is in the background, Miley's phone is in her left hand and her right hand is on her hip, but in the next shot as she shouts, pretending the noise is Jackson, the phone is in her right hand and her left hand is on her hip.
When Miley is hiding the newspapers under the couch, several fall to the floor. When Lilly skateboards in, they are no longer there.
When Lilly discovers she is invited to Kelly Clarkson's party, she runs straight outside and begins dancing. Both doors are open. Then Miley goes and talks to her dad. Miley says "Look!" (Because of Lilly's crazy dancing) and the close up of Lilly has only one door open, not both and nobody went and closed the door.
In several episodes when the beach is seen in the background, the waves are obviously not moving.
When Kelly is calling the Hannah phone, Lilly just picks it up, without pressing any buttons before answering the call.
When Jackson is bald you can clearly see the bald cap that he is wearing on his head. Also, when Jackson has the blue Mohawk hair, you can clearly see that he is just wearing a wig and his real hair is underneath it.
Whenever Miley goes to open the door for Lily to come in, she is clearly standing on the other side of the door waiting for her cue to skate in.