Technically, the answer to covering most complex convex or concave panels:

After placing 3M Fine Line tape (1/8th, 1/4, to 1/2 inch width) around the perimeter of individual panel, use the narrow edge of a straight edge placed upon the surface of the individual panel. Rotate straight edge from the highest or lowest point in the compound panel shape. This serves to identify the largest contact patch and the % of the panel the patch represents. The largest contact patch area and shape is rarely parallel to any panel edge. (Re-read that paragraph)

After cutting a piece of Flite-Metal slightly larger than perimeter of the panel taped to the airframe, peel off the backing and place the aluminum down onto the surface as parallel to the taped perimeter as possible.

Before you proceed to use your index finger to lightly press from the panel center outward to the perimeter, locate the compound curve contact patch direction and area. Initially apply Flite-Metal from the straight line representing the center of the contact patch...using your index finger. As you move from this straight line contact patch press evenly in all directions as you move outward burnishing the Flite-Metal proportionally as you proceed.

Slowly work stretch to perimeter of panel where it will be burnished against the hard edge of the 3M Fine Line tape. Cut along hard edge of 3M Fine Line tape with hobby knife and pull up waste aluminum and tape before final burnish of panel perimeter.

Some false assumptions about panels on "familiar aircraft": Most aircraft during the first three years of WWII incorporated overlapped panels, and balance of the aircraft in WWII incorporated combinations of overlapped and flush, or butt seam panels.