Thanks guys.
I found this article on zenithal airbrushing which is what I believe is the technique I've seen being used - www.dakkadakka.com/.../Zenithal_Airbrushing%2C_OSL_and_Snow_and_Ice_Tutorial%2C_subject_-_Grey_Knight
I think though that I'll stick to using my airbrush for undercoats and base coats, I don't have any spare figures to practice on, the 2 I do have to paint I don't want to keep stripping. I've already had to try stripping one that I painted some 15-20 years ago, which is metal, with Fairy power spray, because it was badly painted, even by my standards, and it was the wrong colour. Yet to find out how that's turned out though...
I'm not all that confident with my airbrush either, and I'm not sure it works right in the first place, being an el-cheapo airbrush (probably worth about £5, retails for about £10!). For one thing I had problems getting the paint to flow properly whilst doing the SEA camo on my Jolly Green, and I was using Vallejo model air paints which are supposed to be made for airbrushing without thinning. Although I've had to buy a replacement of the same model as I broke the nozzle on the original one I had so perhaps the new one will work better...
Very nice figure by the way jgeratic, I can only hope to ever be that good. I'm guessing it's a large scale figure, if not that's even more impressive.