Having a model that exactly matches the shape will definitely help.
Here's something to keep in mind when trying to recreate yourself in any medium. We are very much used to viewing ourselves in the mirror. When we see a direct representation of ourselves, it is a flipped image of what our brain is used to, so it will appear to be different.
When addressing students I've always said that the biggest part of the rendering process is lighting. Good lighting can make an average model with average textures look quite pleasing. Whereas, a high quality model with high quality textures and poor lighting won't look very good.
If you're working from photographs, remember that the photo has perspective and a specific field of view. If you're trying to match your model to photo reference in the top, left or front views, it will be off; those views are orthographic.
When sclupting a model, ZBrush is my tool of choice. I like to have the photo reference in front of me while I work. By default the FOV in ZBrush is awkward. By trial and error I've come to use a FOV value of 20 as my default. Try to match every angle of the geometry with the photo reference.
For texturing ZBrush's polypaint works okay, but I prefer using a combination of Photoshop and Mari. After unwrapping the UVs in Max I will quickly lay down colour by means of photographs in Photoshop to get things started. Then I bring the model with texture into Mari to do some high quality projection painting. From the main colour map I can extract bump details.
Keep referring back to your photo reference throughout this process.
Here's a big tip:
Show your work around and get feedback from others. If the only response you get is "It looks good", try another source.
Alias/Wavefront Maya 3 -> Discreet 3DS Max 4 -> ...
Win7 Pro 64
EVGA Classified Super Record 2
Dual Xeon Hexa-Core, 48GB RAM
GTX 780 x 2
Corona Renderer, mental Ray