Painting with pastels

I've never used chalk pastels before. But, some great model buildups praise them and I decided to incorporate them into my weathering technique. Combined with some airbrush work they definitely are well worth the praise. Below are my results and a brief 'how-to' on the top turret:
I used a few colors from a set of 12 earth tone chalk pastels. Using sandpaper, I made chalk dust that I could load onto a small brush and then apply to the model. Thin washes were achieved by dipping the brush in water then picking up some pastel dust. For the scorch marks/blast hits, I took my airbrush with thinned down Neutral Grey and first created the soft burn-like pattern. With a fine brush, I hand painted the dark cores with German Grey. Then, I highlighted the core edges with a mix of Titanium White and Light Grey. Finally, I gently spattered some very thin Neutral Grey onto the entire assembly with a toothbrush.