(all) done with smoke and mirrors

Done using trickery, deception, or misdirection. Before computer-generated effects, fantastic, unbelievable things in movies were all done with smoke and mirrors. The military operation was completely unseen, completely unnoticed by anybody, as if it were done with smoke and mirrors. The company's CEO managed to swindle his clients out of millions of dollars, and it was all done with smoke and mirrors so that no one would notice the disappearance of the money until it was too late.