From the Phlearn YouTube Channel:
Anyone can create the invisibility effect, the key is taking the right pictures to make your job easy in Photoshop. In this tutorial, we guide you through the process of taking multiple photos and provide tips and tricks to make the job easy and fun.
The basic idea behind making yourself invisible has to do with taking a “base image” of yourself or anyone else and then taking supplemental photos to composite over top the base image.
Quick Tip: Focus on photography, most of this effect is completed in camera.
For example, if you want to make your head invisible, you would take a photograph of your head and then another photograph of your shirt in the same place. When you combine these photos together, it will look like the shirt is filled out from the base photo, but there will be no head from the photo of just your shirt.