Pencil Sketch

1. Ctrl + J to duplicate layer
2. Select the new layer
3. Image > Adjustments > Desaturate
4. Ctrl + J to duplicate desaturated layer
5. Image > Adjustments > Invert to invert the new layer
6. change the layer's blend mode from Normal to Color dodge
7. Filter > Other > Minimum
8. Adjust radius to 1 pixel