I have just started art classes but before that I had no art training. I have been experimenting with different ways to produce sketches. My current favourite is rather like water colour painting:
1. I sketch them in pencil. This allows me to erase and redraw many times. I can’t make smooth lines with the draw feature in the computer.
2. I scan the sketch into my computer – using a grey scale scan at 100 DPI, to keep the file size reasonable.
3. I use Paint.net to adjust the levels so that the picture has the right degree of contrast and the background is white.
4. I use the cloning tool to get rid of unwanted features in the black and white image.
5. I add shading in a new layer using a dark grey with a very low opacity – often below 10%. I use a paint brush tool to do this. I continue to add until I get the tone that I am seeking. I find it hard to get smooth graduations of grey so I use a Gaussian blur over a selected area or over the entire layer to get rid of any blobs and lines.
6. I add another layer for colour, exactly as for shading. Again I use low opacity so that the other layers are visible.

7. If required, I add another layer for writing, e.g. for dialogue boxes.
8. I save as a jpeg so that I can load into wordpress.com.
As you can see my standard is not very high! Hopefully others will be encouraged to contribute their own sketches. It is good fun to try.