Order of Construction
Aside from all the pinning that goes in to garment construction, the neck facing is the single most time consuming process of construction. Once you have that done, the rest is fairly easy. From beginning to end, cutting out to hemming, takes about 4 hours. This includes the neck facing. So here it goes.
First, lay out the four gores so that the straight edges are all in, with the angles flaring out. Next, lay the four gussets out, one on each gore, so that the two sides of the triangles line up on the angled and top edges.
Pin and stitch. Finish your seams however you would like. For this one I flat-felled each seam during construction. But you can try French seaming or even just pink the edges to prevent fraying. Whatever works for you.
Next up, take two of your gusset/gore combo pieces and pin them to one sleeve on each side, with the top edge of the sleeve being the edge where you marked the center of the shoulder seam. Pin right sides together, making sure the gore is at the top edge with the gusset extending down along the side of the sleeve.
Pin and stitch, finishing seams as you go. Step three is to pin one of these gore/gusset/sleeve combo pieces to one side of the main tunic piece, matching that center mark and bottom edges as you go. Stitch this together, finish your seams.
Step four is to fold the tunic in half at the shoulder seams and stitch the sides together, matching at sleeve and hem line and where the gussets connect to the sleeve and gore.
And voila! It’s all over but the hemming.