At the heart of Macbeth is a struggle for power within a relatively closed society. In the script, that society is the noble clan structure of Scotland. This translates well for those who wish to cast the play within many given cultural groups, as many cultures have had similar power struggles throughout their history and lore. At the same time, an all-female or male cast turns some of the original gender roles in the play upside down. By opening up the casting in a production of Macbeth to include a wide variety of cultural groups, or by imposing no cultural barriers at all, you gain access to a huge number of talented actors that might have otherwise been eliminated from contention for many great roles.
When looking for staging or design ideas to inspire the show, look at organizations in which a struggle for power is common. The mob, a corporation, a modern government and many other organizations are fraught with examples of serious struggles for power. Staging a production of Macbeth in any of these settings works well. A traditional Scottish setting offers something for Shakespearean purists.
There are certain themes and design impositions that have become quite worn out when it comes to stagings of Macbeth. The most common of these is the sort of "post-apocalyptic" twist on the costumes and design. The "Mad Max" inspired design of Macbeth playing out in some sort of post-nuclear wasteland has been done over and over by theaters large and small to the point where it has become a cliche.
One of the problems with many Shakespearean texts is that they are difficult to produce given the constraints of modern theatrical budgets, especially in smaller theaters. Shakespeare's plays often include many smaller parts, and most modern theaters simply can't afford to pay that many actors. As a result, many artistic directors take liberties with the text in order to fit within the restraints of casting budgets. Sometimes directors also want to trim the play's for running time. Macbeth does not need any shortening, though, as it is already the shortest of the bard's tragedies. However, you can combine certain roles in order to reduce the number of actors needed. Caithness, Angus, Menteith, Hecate, Young Siward, Seyton and others, as well as all the assorted unnamed characters, can be double-cast or combined.