I want to create this (maybe complex?) special effect, in which a 3D holographic cube floats above a person's hand. A little like the Iron Man hologram sfx. Could anyone give me a kick in the right direction? I know I'll probably have to use motion tracking, but some help to create the hologram effect as "realistic" as possible would be a big help as well.
Just try doing a search on "creating a hologram in ae" and you'll find dozens of choices. It all depends on what you want it to look like - there's no definitive look for a "real" hologram. It's a matter of stylistic choices.