That sounds really useful, but I've tried every combination I can think of, and tried to read documentation, but I can't get my Mac to do that. I press command

That sounds really useful, but I've tried every combination I can think of, and tried to read documentation, but I can't get my Mac to do that. I press command+tab, keep holding command, and then press up or down arrow, and the list of application icons just fades from view. Any chance you could point me in the right direction?