Photo to Sketch

Here is the photo I am using for this tutorial. Feel free to use it, if you'd like.

Copy your photo into a new document and name ir 'Original'. Duplicate the layer 'Original' and rename it 'Desaturated'. Desaturate the layer 'Desaturated' so that it has no color by hitting Shift+Ctrl+U (Mac: Shift+Command+U). Duplicate the 'Desaturated' layer and name the new layer '1'. Now go Filters>Blur>Smart Blur and use these settings:

Radius: 60
Threshold: 100
Best Quality and use Edge Only.
Click OK and invert the layer, now apply a Filter>Blur>Gaussian Blur with a radius of 1, and set its Blending Mode to Hard Light (which can by done in the upper left corner of the Layers Palette).

Duplicate the 'Desaturated' layer, rename it to '2', and move it over layer '1'. Now go Stylize>Emboss and use these settings:

Height: 1
Amount: 119%
Click OK and set the Blending Mode to Hard Light. Duplicate the 'Desaturated' layer, rename it to '3', and move it above layer '2'. Apply the Filters>Blur>Smart Blur filter once again but this time use:
Radius: 10
Threshold: 100
Best Quality and Edges Only.
Click OK. Invert the layer and set the Blending Mode to Multiply and Opacity to 40%.

Once again, duplicate the 'Desaturated' layer, rename it to '4' and move it above layer '3'. Apply the Filter>Styling>Glowing Edges filter with these settings:
Edge Width: 1
Edge Brightness: 7
Smoothness: 6
Click OK and invert the layer. Set the Blending Mode to Multiply and the Opacity to 40%. Duplicate the layer '4' and Filter>Blur>Gaussian Blur it, use a radius of about 3 - 4 this will give us that shaded look. Set the Blending Mode to Multiply and Opacity to 100%.

Adding Color:
Duplicate the 'Original' layer and name it 'Color' and move it to the top of all the layers. Set its Blending Mode to Hard Light, duplicate the layer 'Color', and set its Blending Mode to Color. Here are the finished results.