Famous artists such as John Singer Sargent, William Blake and Dante Gabriel Rossetti have created pictures depicting characters and scenes from this play. Use the rich detail of one of these paintings or drawings as the focal point for your "Macbeth" poster, and you won't have to create your own design or reproduce photographs for your production. Whichever image you use, painting, drawing or photograph, it must be available for reproduction as part of the public domain. If you use an "old-timey" image, consider describing your production details on the poster with a font or typeface that recalls posters of the 19th or early 20th centuries.
Photograph the actors playing Macbeth and Lady Macbeth with blood-stained hands. You can exaggerate the blood for your poster image by staining their clothes and adding a bloody knife to the photo. Consider staging photos that suggest the intention behind the murder of King Duncan by showing Macbeth and Lady Macbeth, both with their hands on a blood-stained crown. You could also photograph the deranged Lady Macbeth of Act V who sleepwalks and attempts to wash invisible blood from her hands. These images can be created by drawing these characters for your poster rather than photographing the actors.
You can depict the witches or "weird sisters" in the play in many different ways, depending on the staging of the production. Consider drawing three mysterious hooded figures pointing bony fingers. You can also suggest the presence of the witches on your poster by photographing or drawing their cauldron. Alternately, consider peppering your poster with some of the witches' famous lines -- such as "Double, double, toil and trouble" and "By the pricking of my thumb/Something wicked this way comes," or "Fair is foul and foul is fair" and "When shall we three meet again?"
Blood is a primary image in the play, so drops and splatters of blood could create an arresting image for your poster. Combine the blood-red color with other significant images from the play -- such as a crown, the trees of Birnam Wood or the candle that Lady Macbeth carries when she sleepwalks.The recurring image of murder and death could be represented with weapons such as knives and swords or skeletons and skulls. Consider depicting the symbolism of dark magic with an image of the raven mentioned by Lady Macbeth. Creating a dark, moonlit image of a castle or battlefield could also be used on your poster to evoke the ominous and dark tone of the play.