To begin my zombie I choose these three photos (Portrait, Skull,and Texture):
Ok, to start we are going to open the portrait photo and with the Smudge Tool (R) we are going to cover the girl's nose and mouth, you can use the Stamp Tool (S) too if you like.
After we do that we are going to bring the skull photo in here and adjust to fit her face. I lower the opacity on the skull layer (after you done go bring back the opacity of the layer to normal) just so I can see her face on the back so I can re size the skull using Edit>Transform>Scale and fit right over her face as you see here:
Now that the skull is over her face we are going to take off the excess by creating a layer mask on the skull layer and painting black all around the skull living only the main part of it as you see bellow:
Now that we have the skull exactly where we want to, we are going to put the texture right over her face with the skull.
We are going to add a layer mask to the texture layer and paint the layer mask to leave only her face and parts of the skull with the texture as we see here:
Now that we have the skull and the texture where we wanted we are going to work the layers a little bit so the image will look better, first on the texture layer we are going to set the layer mode to Overlay and set the Fill to 48%.
Now on the skull layer we are going to desaturate the layer by Image>Adjustments>Desaturate now that we did that we will set the Opacity to 65% and Fill to 80%.
The result should look like this:
You notice her face looks a little weird, we have to change the colors to make it look better and for that we are going to duplicate the first layer (the portrait layer) after that we are going to desaturate the layer, notice that it looks really good now that all the colors blended, but I don't want the image to be black and white so I will create a layer mask on the portrait copy layer and I will only leaver her face showing on black and white:
This is what your layers should look like:
Looks good but we want to put some color on her face, we are going to create a layer on top of all the ones we already have and paint it dark brown, we only want to apply the color on her face so we are going to put a layer mask on the color layer and leave only her face (this time is easier because we already selected her face before on the portrait black and white layer, so hold ctrl and click on the portrait black and white layer mask that the selection will show)
The result should look like this:
Now all we need to do is change the layer mode to Soft Light and the Fill to 58%, here is the result:
Ok, We got her to look like a zombie, now we want to make this a better composition. Starting from the background, we are going to select the girl and create a layer mask on the portrait layer, leaving only her body on the image, now we are going to create a new layer, move this layer under the portrait layer and paint in a dark way to make the background look better as you see here:
Now let's add some atmosphere effects. Create a new layer on top of the others and go to Filter>Render>Clouds. Your colors should be black and white. Then with the Eraser Tool(E) delete the area covering the face of the zombie. After that, change the Blend Mode to Color Dodge.
Duplicate the Zombie Layer and go to Filter>Other>High Pass. Use 3 pixels for the Radius. Then change the Blend Mode to Hard Light.
First paint some blood on the zombie. I used a blood brush, you can download it here. The just apply some Layer Styles. Use Color Overlay with a very dark red and Multiply for the Blend Mode. Then add a Bevel and Emboss. Use Inner Bevel for the Style, Smooth for the Technique, 100% Depth, Up, 1px Size, and 2px Soften.
Duplicate the Zombie Layer again and go to Filter>Blur>Gaussian Blur. Use 5-10 pixles for the Radius and change the Blend Mode to Soft Light.
You can add some new effects like Adjustment Layers with Hue and Saturation reducing the Saturation and make the image darker. Also you can add more blood stains, or simply whatever you want. As it is a zombie, there'r no parameters of what is right or wrong.
Download the PSD File
Click here to download the Photoshop file used for this tutorial.