First Attempt at Pre-Shading, Right or Wrong?

Matt, looks good from here.

You can vary the shading effect by the number and density of top coats you apply, so the pre-shading doesn't have to be spot on.

You can also lighten the centre of panels with white, for those high traffic areas like wing walks, to provide a faded effect.

What I find with pre-shading is need to leave it a little more obvious than looks right, as this compensates for the numerous clear coats, which have a tendency to dull the effect.

Best bet have a play on some scrap card or a plastic bottle, to get a feel for the technique.

Karl

Right or wrong depends upon what you are trying to achieve.  What you have done looks to be consistent with the current rage among a lot aircraft modelers.  Perhaps a few of them could be wider, i.e forward line on right horizontal stabilizer is better than it's counterpart on the left.  On the whole however, what you have done looks very similar to what many people are doing for preshading, and in that sense you are probably very much on the right track for what I gather you are trying to achieve.

On the other hand, in real life the edges of panels don't display any marked darkening, and the panel lines themselves are hardly noticeable, so the effect while looking very cool, takes away from realism.  I think if you're not perfectly regular in hitting every panel line and also randomly shade in the centers of panels and across panels in a more blotchy fashion, you'll achieve a much more realistic look, particulary if put down enough of a top coat to make the preshading extremely subtle.