ralphee said:
Id have actually advised to stay away from Pastels, the end result is not all that great, but then, it depends what you are building.
If its a studio scale subject, avoid them, and do it the old fashioned way, using gauche washes and water based smudges.
Oils too if thats your bag, though i find water based and acrylic washes work better and tend not to spread too much.
Graphite, great material to add blast marks or metal sheens too.
A lot of it you tend to find along the way, but as for pastels, to me they are a slippery slope and dont look all that great outside of smaller aircraft/armor modelling.
lee