Norman women's clothing consisted of an undertunic and a bliaut. The bliaut is characterized by long flowing sleeves, a tight bodice with horizontal folds, and a very full skirt (sometimes with a train).
In order to do this without a waist seam, it's necessary to cut the skirt with gores, and the torso area longer than the actual torso of the person wearing it. In other respects, it's a very similar layout to the undertunic that it's worn with.
First, you need to measure yourself:
Then you start to do the math.
Take a piece of paper, and draw a representation of some yardage. (I usually use 10 yards for a trained bliaut, but I'm fairly tall, and well rounded) You're going to have to do this for every piece of material you make a bliaut from, because the optimal layout will depend on the width of the fabric and how much you have of it.
As a guide, this is an idea of what you'll end up with:
Draw a rectangle on the "yardage" that's as wide as half of M2 (all measurements are plus whatever seam allowance you like to work with) and as long as M1.
Depending on your height, circumference, and fabric width, you'll have space left over on the the paper to draw in the side gores (there will be four, and to make them, take M4, and whatever width you want them to be (as you can see from the attached drawing, I usually use the rest of the width of the fabric) and then put one above the other. Then you cut them into triangles, as in the drawing.
Then you're going to take M4 again, and that will be the height of each of the front and back gores. The sleeve gets taken out of the left over bits.
Depending on how long the main body piece and the side gores are, sometimes the sleeve tops and underarm gussets can come out of the leftover between the bottom of the side gores and the top of the back gore. (ie if M4+M4 is much less than M1, there'll be leftover)
As for the dimensions of the upper sleeves, make them M6 long and about 4 or 5 inches wide. Do a sanity check with the 4 or 5 inches plus the sleeve to make sure it won't be either way above your wrists, or completely covering your hands. The gussets should be at least 4 inches square before you cut them into triangles.
These instructions assume you're not putting a train on it. If you do, then figure out which is the front and which is the back, add the length you want the train to be to the length of M1, the back gore, and two of the side gores, and adjust from there.
Once you've drawn it, and are sure you're happy with the numbers and the layout on the fabric, then you cut. I generally just use a tape measure and a pair of scissors, but I'm fairly fearless.
Now, on to the sewing layout
The Norman Women's Clothing Page is republished on The Garb Index by the kind permission of Adrienne Dandy.