Purchase a type of acid-free paper. The heavier the "tooth," the more pigment the paper will hold. You have a choice of many colors of paper, which will show through the pigment and pull your painting together in the end.
Make a thumbnail sketch. You always want to have a plan for your painting before you start.
Start to paint with a light touch, not filling the tooth too fast. Block in the shapes with loose random strokes. Choose to paint with dark values first, saving the lighter values for the end. This will prevent muddying of your colors.
Layer the pastels to build up color and texture.
Distribute light and dark values throughout the painting to make it more interesting.
Blend the pastels lightly with your finger on the first layers of the painting.
Vary the strokes you use. Switch between swirls, crosshatch, and dabs.
End the painting with bolder, heavy strokes of brightly colored pastels.