There’s a lot of ways that effects are done poorly in films. Obvious compositing or digitally rendering characters, these things can kick you right out of the dream when you’re watching. The most, well, _effective_ effects are the ones you notice the least.
Here’s a whole reel of just that.
[Heads Up from Slashfilm](http://www.slashfilm.com/the-wolf-of-wall-street-fx-reel-showcases-invisible-cgi/)