Noble Kreative shows a method for building a custom kaleidoscope effect in Ae.
While After Effects has its own kaleidoscope effect, you can experiment with different looks pretty easily by making your own. In this latest motion graphics tutorial, Najib Khayati (Noble Kreative) shows how you can make one with expressions (mostly unwritten) and a couple of control. The project becomes an audio visualizer too. The procedural kaleidoscope setup animates to the music.