This section is from the book "Clothing For Women: Selection, Design, Construction", by Laura I. Baldt. Also available from Amazon: Clothing For Women: Selection, Design, Construction.
Baste seams with regard to the type to be used. Fells (hemmed or stitched) are best for the shoulder seam because they are flat, and either fells or French seams may be used on the underarm seam. Baste the seam of the sleeve.
Try night-dress on to see that the shoulder seams, neck and armhole lines are good. While the dress is on, have the line at the lower edge turned, the length to be determined by individual taste. Marking at the floor will in very thin materials allow enough for shrinkage. Let the material lie on the floor, the gown hanging straight from the shoulders. Put a line of pins from center front to center back, along the gown where it touches the floor. Remove, see that the line is good, fold gown through center front and back, edges even, and trace just below the pins. Measure from the traced line, the depth of the hem, plus one-quarter-inch seam; mark with pins, and trace; remove pins on tracing. Cut through both thicknesses of material.
Stitch and finish the shoulder seam (fell). Rip the bastings from the underarm seam, so as to lay neck out as flat as possible on the table, unless one has a dress form, upon which the gown should be placed, to apply the lace. The finished line of the neck being marked by the edge of the material, the lace edging must be placed far enough below the edge of gown to allow the beading and lace to be placed above, the lace to end on a line with the edge of the material (Fig. 155). Pin to place, letting join come on shoulder. Join according to directions for joining lace, Fig. 157. Baste the lower edge of the insertion to the gown, holding it easy so it will not draw the material; hem this edge of the insertion to the right side of the gown. Gather the upper edge of the insertion (using a plain hemming stitch), to fit the neck of the dress; overhand beading to insertion, gather upper edge of beading as insertion was gathered. Overhand the lace edge to the beading. Then cut material of gown away one-sixteenth inch above lower edge of insertion and whip the raw edge down to edge of insertion. The" lace should be applied to the sleeve in the same way, either on straight or curved edge. For detail of trimming see Fig. 155. The ribbon beading may be omitted or not, as fancy dictates.
Stitch underarm seams and finish (fell or French seams).
Lay hem; take fulness in hem out by fine gathers after edge is turned, or in tiny plaits; baste, and hem by hand or stitch by machine. If the latter, stitch on the wrong side, without thread in the needle. Turn and thread needle, stitching on the right side through the needle-pricks.
Measure one inch from shoulder seam on the back of the garment; fold the armhole in half and at the point on the opposite side from the one-inch point place a pin.
The seam of the sleeve is put to this point. Then lay the shoulder seam and the underarm seam of the gown together and fold armhole in half. The fulness of the sleeve is gathered in between these points on the top of the armhole. Place the seam of the sleeve, right side of sleeve to right side of waist, at the point indicated for it; pin it to place, holding the night-gown toward you as far as the sleeve is to be without gathers. Then holding the sleeve towards you, gather the top of the sleeve between these points, and adjust the gathers, having sleeve slightly fuller on the top, each side the shoulder seam. Baste sleeve to armhole, using small stitches. Try on to see if fulness is adjusted well. Change if necessary. Trim seam to one-quarter inch.