Pastels can be blended with fingers, a tortillion or (for large areas) a rag.
Mingling pastel colors without blending them lets the colors combine visually for a textured effect. A few different ways of doing this:
Top left: Blended
Top right: Layered
Bottom left: Crosshatched
Bottom right: Scumbled
Sharpening a Pastel Stick
To sharpen the edge of a pastel stick, scrape it with an art knife. Use this technique to sharpen Conté sticks, too.