Under-painting in water based paint (acrylic wash or watercolour)
then over-painting in pastel. This simple technique is shown
below in four stages: first picture - draw in the outlines, not details
in light pencil then paint in a wash the first petal; second picture -
apply first layers of pastel; third picture - build up layers of pastels
until desired effect achieved; fourth picture - repeat steps 1-3 for
each remaining petal and rest of painting to finish. This technique
can of course be applied to any subject to equally great effect.
For more ideas like this visit the web site this demo came from:
www.flowerportfolio.com