I did this a few weeks ago, taking pictures for a high resolution skin. I shot on film and scanned afterwards, because I needed the higher quality (instead of using a digital camera). Very important is, that you have a totally flat lighting. I used two flashheads with umbrellas, but next time I will probably use two diffusion screens 2 meter by 1 meter each. Just taking one frontal shot and one shot from the side is not enough, I made this mistake myself. Its much easier to apply it to templates in PS if youve got one frontal shot, one shot turned by 15 degrees, one turnde by 30 degrees and do on. Be aware that the model has to turn, the camera position should stay fixed, otherwise youll get an uneven lighting. Use a lot of powder and (if necessary) a non-glossy lipstick. Take single close ups of all important parts (dont forget tongue (no powder here..;-)) and the teeth). In Photoshop avoid a soft edged cloning tools as much as possible, as it softens your texture in the overlapping areas. All this tips apply to the head. I didnt have the time do make my body texture so far. I wish you good light...