In the drawing below I drew the figure feintly with pencil. I then added blocks of colour with conte crayon and finally using the initial pencil drawing as a guide, I added a strong charcoal line to give form to the figure.
Below is a large but quick study using conte to draw the line straight off and then add colour and some tone to help give form.
The study below I did on coloured Ingres paper. I used soft coloured pencils as the medium. The colour of the paper actually became the lighter tone as didn't use any lighter coloured pencils. For the body I used one colour of pencil and used hatching to achieve degrees of tone. It was a quick study and I see that I could have added more tonal variation to the image.
For the study below I used Conte, charcoal and chalk. I focussed on the model's back (and I don't think I got the legs very well proportioned) but I like the tonal effect I achieved on the back. I put a strong defining charcoal line around it - I do note this can sometimes help with a quick sketch to achieve the contour but sometimes it may overpower and detract from the subtlety of the tonal work.
Below is a larger 'back' study. I think the strong tones depict strength but there is always a danger if trying to be expressive and free with tone using conte that I can put too much colour on and then it can get hard to lighten up areas that get too muddy and dark.
The two studies below are small scale but I managed to capture the subject as she can lie when relaxing. The first was in charcoal which really lends itself to a tonal study. For the second I used crayon, just childrens crayons so not artist quality. I used an orange and orangey brown for the skin and grey and white for the clothes. I built from light to dark with the crayons; they are not so easy to use as they are hard to layer with and you get blobs of crayon after a while if you try and lay it on too much. I liked doing two similar poses in two different media as it demonstrates how you have to change your approach to achieving a tonal study depending on the media you use. It also shows how the media used can add a different feel to a drawing.