With vehicles, it's a good idea to do some pre-shading to stop the surface becoming flat and dull. You can spray or paint black into the panel lines over a grey or white prime and when you put your basecoat and layers down you'll get a better look.
As you've already got a painted model, you can varnish the model and run some wash down the panel lines. Acrylic wash is fine for this but oil washes will have an easier time due to less surface tension. For what you have there, some nuln oil would work nicely.
You could also do some edge highlighting on your blues to improved the overall look.
EDIT: Here's what I mean by panel lining/washing on a Falcon I painted, the effect is subtle, but it helps a lot.