I built the field howitzer a couple of weeks ago, and the crew has been on the painting table since. Really nice figures.
I started by coating them with glue, to give the paint something to bond to, then white undercoat with black wash to bring out the details.
Paints used (Vallejo unless otherwise noted)Uniform: 830 German Field Grey
Trousers: 836 London Grey
Helmet: 869 Basalt Grey
Belt and boots: Black
Washed with Citadel black wash
Skin: 955 Flat Flesh
Shirts: 821 German Camouflage Beige (I think)
Skin and shirts washed with Army Painter Quickshade Soft Tone Ink.
Everything coated with matte varnish.