[Stiglr]

Actually, I've found the solution to this is to create a good texture guide from copies of the actual model's parts.

I create a nice, large square rectangle above my object (since my target game system works best with textures that are square, power of two sizes such as 1024 x 1024 pixels).

Then, I create copies of the parts of my models, drag them up into the rectangle, scale them for size, and "unwrap" them. By selecting and "cutting away" sides and rotating them into positions where they're facing the camera at a 90 degree angle. The idea is to create a "plastic model flue" picture. I also take care to line things up so that when I actually create a texture, I can easier create panel lines with straight lines. An example being an aircraft fuselage: once it's unwrapped, you have a left side, top side, right side and bottom. I align these vertically so that if I want to create a panel line that goes around the circumference, it's a straight line in the art program that goes through all four (stacked) parts in the texture.

When I've got everything positioned, I make sure the surface lines are showing, eliminate the grid from the viewport, zoom in close to the edges of the rectangle, and take a screen grab of the rectangle and all the pieces in it. After this is done, I can delete all of it, or keep a copy if I might need to revisit it.

Then, if it's going to be some time before I actually create finished textures, I can still texture the model with the "model flue" guide, lining up the actual surface lines of the texture guide with the surface lines of the 3D objects, so that I know the finished texture will mate to it. All I have to do is change the texture file assignment and voila.