Developing a "redhead bust" typically refers to the artistic process of sculpting or painting a portrait of a redhead, or alternatively, following a curated beauty and style guide designed specifically for redheads. In the context of artistic creation, it involves capturing the unique tones of red hair and the often-sensitive complexion associated with it.
If you are working on a physical or digital bust (portrait):
For developing a personal style "bust" (head and shoulders look): Redheads Guide to Eyebrows