Some of us may never get close enough to a Hello! Project member to be able to draw them. And if you do, you probably will not have the time to draw anything other than a quick sketch (unless you are a hired portrait artist... blah blah blah) Anyway, since most portraits are time consuming, lets stick with a picture.
I have selected Maki because she's hot... ^__^
I mean, since making a drawing look like her takes some doing, it would be good to select her as the model. Secondly, the 3/4ths angle (45 degree turn from the camera) of her face produces decent shadows and more depth to work with.