I started with a black primer, as I had primed it this color in anticipating of painting them for an event that I took a different army too last year. I would have preferred to do this backwards, start white and work my way back, but it ended up working fine. All of the colors I used in this are Krylon primers. I really like this line of paint for priming as it covers well, doesn't gunk up, it's inexpensive (around 5 or 6 dollars a can) and has a great spray head that works in a flat fan pattern, not a cone.
I masked off the tank using 3M painters tape.
I spent some time weathering the model after this and it brought the white down. You can tell in this picture that the three colors are way too different, and it's a bit distracting. The weathering helped unify the model.
I'm still not done, but I think I've got a good start towards a great model that I didn't spend much time on. I think I've spent about 30 minutes of actual work up to this point. It's not going to win any awards though if I need something on the table quickly this could work.