Used one of my wedding pictures as a reference.
Info stuff:
~6 Hours SAI Painter
Mainly using Brush + Pen tools
Pretty good. I think that maybe the mouth is not super well-defined, and also the tip of the nose appears to be a corner, rather than rounded. The hair isn't really casting a shadow on the skin, either, which damages realism a bit, I think. Also, the eyes have no 'shine' on them, which is a trait not normally seen on living people.
Link
Atatstsi
The shading under the chin is spectacular! <3