The location where you need to tap is important. The tree climbing level is not difficult when you know the exact location of where you must tap. The best way is to tap Clarence's feet as fast as possible. If you tap anywhere else, he will not climb. Keep tapping until he makes it up to the laundry basket. You can also tap with multiple fingers to do this faster. Faster tapping also is useful in the firefly collecting mini-game, the piņata punching mini-game, and the inflate the balloon mini-game.
Finding Clarence in the ball pit
Look for his eye or part of his cheek to appear from the balls. Until then, tap with multiple fingers as fast as possible until you see something pop out of the ball pit.