In this tutorial, I'll teach you how to make magic eyes that just float in midair, not attached to anything. It's rather useless considering you could use invisible hologram, but I'm sure someone might find a use for it.

First, make a fairly complex shape that is in the place and layer you want the magic eye in - you can't move the magic eye to another place without attaching it to something, once it's floating, so get it right the first time.

Then, break out your corner editing tool on the shape. Grab any corner and drag it to the other end of the shape, and should delete it. Using normal triangle won't work (at least not on the very last corner, I'm not sure about the ones before it.) Rinse and repeat, and when you delete the last corner, the shape will altogether disappear leaving the magic eye behind.

Remember, that because you can't create unattached magic eyes normally, you won't be able to move your unattached eye to another floating place after it's placed, so be warned!

It might possibly work with other objects like decorations or sensors but I haven't tested it yet. I'll edit the post if I find a simpler way.