I tried the scarf trick on a shoot... once. Never again.
Yes, it "softens" the image and helps with skin smoothing, but unless you can test in advance under the lighting you will be using, you may be disappointed.
Since you can do much of the same type thing with an image editor, why bother. Shoot it sharp and add the effect later if needed.
Just my opinion...
I think the image below was done with the scarf in place.
