Trick Photoshop

You can make a sketch with Threshold in Photoshop. It will work with most images.

This is effect you can create.

Or this.

I have opened this free stock image. You will find it here

It belongs to ProfessorDeath

Step 1 : Duplicate the Background Layer by pressing CTRL+J.

Step 2 : Press CTRL+SHIFT+U to desaturate the layer.

Step 3 : Press CTRL+J to duplicate Layer 1 into Layer 1 copy.

Step 4 : Go to Image>Adjustments>Threshold.

The Threshold dialogue box comes up. 

Step 5 : Drag the slider at the bottom to taste. Click OK.

And, here is the sketch.

Step 6 : If you want to play around further click on Layer 1.

Step 7 : Change the Blend Mode of layer 1 to Overlay.

Step 8 : Click on Layer 1 copy and change the Blend Mode to Hard Light.

Step 9 : Lower the Opacity of the layer to 55%.

This is the finished image.

Other Photoshop tutorials are here