I agree with Mr.B on the white. I add a little bit of grey and/or tan, just to take away some of the "starkness". I also never go with straight black (add a touch of white to it).
Anyway, to throw another method pre-shading your way...
I spray the whole model in black/very dark grey, then "marble" it with white...leaving the panel lines dark. I find this far less tedious than trying to keep a decent line on just the panel lines. It is far more time consuming though....and having shaky hands actually helps a bit!
For color coats, I thin the paint down about 50/50 (I am using enamels....zero experience with acrylics)...spray in thin layers, to slowly build up the paint. This will give you a blotchy, weathered looking finish.
Other colors hav been added already, but you can see a bit of the "blotchiness" on the large panel, just in front of the first round window.
It shows better to the eye...doesn't really show too well in pics.
Here's another example of the effect...
Regardless of what method you choose, I'd recommend that if you're going to preshade the bottom...presade the whole thing. Even with the darker blue on top...if it's thinned decently, you'll still be able to see the preshade...unless you spray too much.
Welcome....enjoy!