I think using a hologram or a partially see-through mirror would be a good way of conveying to the audience just how unsure he is of what he is seeing. If he did it facing a large mirror in which his reflection in the mirror is trying to grab the dagger it then it would also be a good way to symbolize the internal struggle he is having between himself over actually going through with the murder. When he first notices the image of it in his reflection he would back away from it, but then as he starts feeling less guilty about it he approaches the mirror. There would be sounds of thunder and a howling wolf in the background after “witchcraft celebrates Pale Hecate’s offerings”. As Macbeth paces infront of the mirror the sound of his footsteps would be exaggerated to be louder to give it a more ominous feel to further allude to “Tarquin’s ravishing strides” The lighting would be dim and illuminated with torches or candle light to further add to the creepiness of the scene.
