How do you determine shape and color for eyebrows if there is no hair whatsoever?

For those clients who have little to no eyebrow hair to work with such as those with alopecia, I determine the shape and color by drawing on the eyebrows using the actual tattoo color to get a close approximation of the results of the tattooed brows prior to actually implanting in the color (which is done with fine needles). The key is to give each client the brow that looks best on him or her, always taking into account any personal preferences of the client.

No eyebrows due to alopecia universalis
No eyebrows due to alopecia universalis
Tattooed eyebrows on client with alopecia
Tattooed eyebrows on client with alopecia