First off I use Ultracote exclusively. I have done several covering schemes where the film seams did not follow the structure of the component being covered. In these cases I construct a single sheet, or panel, of covering made up of several pieces of covering and cover as usual.

Cut the panel pieces: I build the covering "panel" on a large piece of glass (ex bedroom door mirror). The individual pieces are cut and laid out on the mirror. Account for 1/4" or more overlap and cut the next piece. Use patterns made of heavy construction paper if needed.

Join the panel pieces: With all of the pieces of covering cut, start with the piece that will be positioned towards the rear first. Lay it out flat on the mirror and tack it to the glass with a warm iron (just enough to activate the glue). Don't worry, once the adhesive is cool, the covering will easily peel up from the glass. Lay the next piece overlapping the first by 1/4". Carefully heat the overlap with a warm iron - keeping the panels flat. Continue until the panel is completed.

Cure the panel pieces' seams: When the tacking is completed go over all of the seams with a hotter iron (but NOT shrinking hot) to fully activate the adhesive. Wait until cool.

Remove the panel: Peel the completed panel from the glass.

Cover with the panel: When covering the plane's surface treat the entire panel as a single sheet of covering. Caution, don't stretch the heck out of it. And, when shrinking with a heat gun, using light cardboard to shelter the seams.

Pic 1 - finished - wings, fuse &tail are all panels
Pic 2 - assembled wing top panel (not tacked yet)- checking for fit
Pic 3 &4 - pre-assembly positioning of panels
Pic 5 - wing bottom panel components
Pic 6 - wing bottom panel tacked on mirror
Pic 7 - covered wing top