STAY STITCHING
    
    I've never felt the need of stay stitching, so this 
section is composed entirely of whole cloth and rumor. 

    Stay stitching is straight machine stitching done around 
the raw edges of garment pieces to keep them from stretching 
out of shape before they are sewn together.  Whenever I read 
an impassioned exhortation about the dire necessity of 
always stay-stitching everything, I wonder "What are they 
<em>doing</em> to that poor piece of fabric?"  Perhaps it's 
a clue that one such exhortation added "And never pick up a 
partly-assembled garment by the raw edge of the neck."  

    When I learned to sew, stay stitching was done about a 
quarter inch from the raw edge -- this allowed the stay to 
double as a stop to ravelling; seams on everyday clothes 
were pressed open and left raw, or at most pinked, in those 
days.  Since ravelly fabrics were mostly not available and 
we made most home-sewn garments out of cotton print, raw-
edged seams worked quite well.  (Now that I'm making 
everything out of linen, I flat-fell all seams.)  
    Nowadays, I read instructions to stitch as close to the 
seam line as you can without risk of showing on the right 
side, which makes more sense in terms of stabilizing the 
seam line, doubles as a stop to seam-slippage, and leaves 
room for the ubiquitous overlocking.  (I deal with seam 
slippage by leaving fabrics that are apt to pull at the 
seams in the store.) 

    It is, of course, very important to refrain from 
stretching the edge out of shape while you are stay 
stitching -- it not only does no good to stitch after the 
edge is stretched, stitching will prevent un-stretching as 
efficiently as it prevents stretching.  
    To this end, you always stitch with the grain -- that 
is, in the direction that would smooth ravels, rather than 
roughing them up.  A neck curve should be stitched in two 
installments, each starting at the shoulder and ending in 
center front or center back.  A shoulder seam would be 
stitched from neck to armscye, a side seam in a flared skirt 
from hem to waist, a side seam in a bodice from armpit to 
waist. 

    For details, you will have to consult someone who 
endorses the practice.