undercoat black. Paint frame in white.
colour the panels
wash with black wash (nuln oil) Note - citadel washes aren't exactly washes really, they aren't watered down paint, but are a formula sort of like using Liquid Future and Inks, so for people who aren't into using 'washes', I really recommend trying out the Citadel (Games Workshop) Washes range. Particularly like how the black goes on things.
Once wash has dried, carefully paint all edges white again (highlight). Put small bit of paint on brush, wipe brush on rim of paint pot to get off excess paint, run side of brush (not tip) along edges, holding object at 45 degree angle to get thin line of paint just on the edges of each shape.