The stencil method can add a little DIY trick to your dry pastel compositions. It allows you to easily obtain forms with very clean contours: guaranteed style and graphic effects!
You can use:
-Masking tape to create straight line demarcations,
-Stencils in whatever shape you want, to bring out the presence of certain elements.
Draw your subject with pencil on a thin sheet of paper (tracing paper, for instance).
Using a utility knife, carefully remove the inside of the subject and keep the contour.
Position this stencil over your work and apply dry pastels evenly inside the contours, making sure to also cover the edges of the tracing paper.
Remove the stencil: your subject will display very regular contours.
Note: so you don't lose the sharpness effect, don't stump the subject's contours. You can also keep the stencil in place while you accentuate volumes, shadows and light.
Some artists compose whole works by sequencing and overlaying stencils. This technique, which is trickier to do, is especially suited to still lifes. This will give your work great clarity and pure forms, whose volumes you can bring out as needed. Your results, unusual for this medium, will be striking.
To prevent any likelihood of dispersing pastel particles, you can stabilize every finalized subject with a fixative before working on the next one.