I want to create a cube with some general extrusions. This should be the same across all sides of the cube. Is there a way to make this mirrored across all six sides? I know that I could delete the rest of the cube, copy my changes, rotate it 90°, move it down and to the side, and repeat for all the sides, then remove doubles, but I'm wondering if there's a way to make this work in real time.
In the below image, all six sides should copy the changes shown here on the one side: