Colorless solvent markers can be used to soften and blend colored pencil, and can create a watercolor-like effect. With watercolor pencils you can get the best of both worlds, using water to blend and overlaying with burnished color. Oil-based solvents, such as turpenoid , can be used to blend colored pencil as they dissolve the wax, but they are toxic and should be used with care. Try them on scrap paper first, and observe safety precautions.
Tortillons (blending stumps) can also be used to smudge and blend pencil, though also lift the pigment a little, giving a slightly grainier effect than pure layered pencil. Try using them in combination with layering techniques. Experiment!

