tips on making faded panels on tanks.

You do need to be careful that you don't cover up the pre-shade with the topcoat. Start painting the topcoat in the center of the panels and feather out the topcoat as you approach the dark edges.

sounds good, ve head that you should thin down the top coat to make the pre-shade more apparent, is this true?

sounds good, ve head that you should thin down the top coat to make the pre-shade more apparent, is this true?

I generally spray flat black around the edges and outlines, then spray the basecoat. As Peridexion said, that's called preshading. After that, i'll lighten the basecoat and spray a little in the centre of the panels to make them even more faded.

That is one way to do it, it's called pre-shading. There is also post-shading. You can even combine the two. Also, try progressively lighten your green paint with some light yellow (not white), and spray these lighter greens near the middle of the panels, with the lightest color in the center.