Creating a Sketch from an Image.
1/. Find an image that will work for you. In this example there is a Kingfisher. The background does not matter.

These are the before and after images.

2/. Image Adjustments/Desaturate. Now the image is Black & White.

3/. Add a New Copy Layer. Layer/New/Layer via Copy.

4/. Image/Adjustments/Invert.

5/. In the Layers Dialogue Window,on the bottom right screen, using the Normal to Colour Dodge. The image temporarily will go white.

6/. In the Filter Menu (down the bottom), Filter/Other/Minimum, 1 px.

7/. You now have a greyscale sketch.

8/. Now to add colour. First select the original background layer.

Layer/New/Layer via Copy.

Move this copy layer to the top of the layers.

9/. Then using the Image/Adjustments/Colour Balance, modify the colours to suit your image and you are done!