Generally my way of working is to start with all the base layers that other layers are built from. I paint the base colour layer for the skin first. Then I skin half the basic panel line, fastener, fabric structure and rivet layers all at the same time. I'll skin one wing, one half of the fuselage etc in false colours, edit them until I'm happy that everything lines up and then copy and paste them to the other half of the skin. This stuff takes week or two to do and can be a bit of a grind at times.
At some point I'll skin all the interior bits as well. This is pretty much a seperate project, with its own layers.
Then I start on all the 3D stuff, creating multiple copies of the base layers to get drop highlights, stronger hatch lines, worn rivets and so on. I also add shadow and highlight effects and create the 3D fabric effects. This stuff is more interesting as you have to think. Also you see big improvements in a fairly short time, a few days normally.
Then I use several copies of the base paint layer to create the camo scheme, erasing different areas of this layer for each new colour. Simple markings are painted right on the skin, complex noseart sometimes gets its own multi layer file and is shrunk and pasted in later. All this can be anything from an evening to a few days to do.
Last thing is the weathering, there might be 20 layers or so and it can take a week or two. I like this as its an area where you can express yourself a bit.
I agree about the Hurri BTW, lots of camo schemes and also a load of interesting 3D effects to do on it. Its one of the more popular MA rides that hasn't been redone yet, so hopefully it won't be much longer.
