Thanks for the tips, everyone! I got the model finished with the advice last night.

I'm trying to make my own custom board gaming dice with an identical indented shape on several of the faces.

Is there some way to make a die face a component and then rotate and copy that face to some of the other sides? When I try to select the face I've made I don't seem to be able to choose Make Component - is that because the die face doesn't have depth? I'm pretty newbie so I hope I'm missing something obvious!