This post will show you how to make some hosen using woolen cloth and a sewing machine. I would be delighted if you tried hand sewing, as I am convinced that it produces a better result but most people prefer to attempt new projects on the machine. I believe, now, that I need to adjust my pattern to remove the ankle seam. Though there is some (very vague) evidence that it could be acceptable, its absence in most illustrations makes me think that it must not be a common feature. First, some background.
http://www.wga.hu/index1.html 1412-1416
Women are also depicted wearing hosen in the Limbourd brothers' February. The lady in blue, seated, seems to have some sort of lumpy ridge around her left ankle and some wrinkled on her right shin. Her shins are also a slightly different colour to her hands and face, implying it is not visible skin. The woman in the background on the left (sorry for flashing their genitalia at everyone) clearly wears reddy pinkish hose, rolled down to under the knee. Since the bulk of the roll under her knee is finer than that of the man pictured in the upper right detail, it is possible that she wears short hosen.
The 15th century artist Israhel van Meckenem created this image. The hosen the woman wears are loose at the knee, and collected by a garter. The pattern is clearly extended straight up from the widest point of the calf. We cannot see if the garter is tied or buckled, though no loose ends are visible. No seams are visible on the front or sides of the legs, or around the ankle region.
France, 15th century, Roman de la Rose, Bodleian Library MS Douce 195, 66v, p. 138
In Roman de la Rose we see a woman wearing black hosen with black shoes. Only the edge of the shoe leather shows up, and there is a similar light line seen under the knee where a garter would sit. Since we know shoes were made from leather and the artist has depicted these edges in the same manner, it is possible that the garter is also made from leather. The woman again wears the hosen rolled down to under the knee, and no seams are visible.
Heironymous Bosch, Adoration of the Child, Detail http://www.wga.hu/index1.html
From looking at the wear patterns seen on images of beggars and workers who had worn out the bottom portion of their hose, it appeared that it was reasonably common for hose to be worn away to the ankle. The logical progression from there is that it would seem sensible to replace hose feet when they wore out, since the remaining leg was still functional. I know that is all conjecture rather than fact - it simply explains my thought process when starting to make hose a few years ago. The image above shows a man sitting in front of a fire with either no foot portion on his hose or a single stirrup strap under the foot - I have a large poster of this image and it is still hard to tell if the line under his foot is a strap or a stick. I feel that he is holding his calf and there is a strap under the foot. Either way, this image was another that compounded my desire to attempt making hose with a seam straight up the back of the leg and another around the ankle. I have been wearing this style for a few years now and can say it is very comfortable and wears evenly. The next batch will be based on another pattern, probably something like this or this.
More pages to look at
This page has some useful related information including an extant garter. This page has a great picture showing some over-the-knee length hose hanging in a workshop, as well as very good information on construction and research.
So, I type this up and have a bit of a search only to find this page. Bettina's website has some new pictures of hosen, including an extant pair from the fourteenth century.
Construction Process
After deciding that I wanted make hose with a separate sole and a seam straight up the back of the leg, I began to pattern. I do not pattern from numbers, rather I pattern directly. That means that to make a new pattern I take some fabric with minimal stretch or stretch comparable to the finished material and I pin it on until it fits. This part of the process means you need to have a good idea of where you want the seams to sit, before you start pinning. The ankle seam came about after finding it was the only way I could get a truly snug fit around the top of the arch and back in to the lowest point on the calf. Evidence does not point to its existence, though it does not comprehensively deny it either. Not great research - more of a work in progress.
1. Make a pattern
This document is not going to show you how to make a pattern, just how the hose are constructed. I will record some instructions to give a rough idea, though.
Draw around your foot onto firm, non-stretch fabric and cut around this shape, making it at least a 2 inches too large. Drape fabric over the arch and pin it as tight as possible to the sole piece. Mark a neat line around the ankle. Try to remove your foot and ease the pattern off 3-4 mm at a time until you can work your foot out - it should be difficult but not impossible. Remember that the ankle will firm up as you sew a seam at that point. Trim the ankle line, remembering to leave 1 cm seam allowance. Sew the sole and upper together and try it on. Make adjustments until you have a nice fit. If this takes 10 goes, who cares. Better to get a good fit. Put the hose foot on and repeat the process to get a pattern for the calf piece.
2. Choose your fabric
I have selected a medium weight wool that has been lightly fulled. This type of fabric was becoming more common in the 15th century. It should be prewashed to reduce the chance of felting, shrinking and dye runs. Choose something that feels all right on your ankles, as there will be a lot of contact. Choose something with at least some bias stretch, as this will give a better fit. To check the bias stretch, look at the threads in the fabric. The grain goes along the same line as the threads, while the bias is along the diagonal line, 45 degrees to the threads. Pull it on 45 degrees to check the stretch. If you are looking for other options, silk hose were known in the fourteenth century and linen lining was present inside garments throughout the fifteenth. Wool, however, has usually been woven to provide the most give and provides warm as well as cushioning, making it ideal.
3. Cut the pieces out
Lay your pattern pieces so they are on the bias. Don't forget to cut a seam allowance. It is useful to mark the seam allowance on each side of each pattern piece.
sole
upper
calf
4. Constructing the Foot
Lay the upper on the sole. Pay attention to marking the left and right soles and uppers as well as the correct side of the fabric. 
Position the seam up the back of the heel. It can help to make positioning marks on the pattern pieces. Spend some time easing the pieces around the curves and pinning in place.
The finished foot.
5. Adding the calf piece
After attaching the calf piece, flat fell the lower edge of the seam.
Sew up an inch of the calf seam and then flat fell upper portion of the ankle seam.
6. Finishing the hosen
Hem the upper edge and try on your new hosen. Don't worry if it takes 10 seconds, 20 seconds, a minute to ease your foot into the hosen. Once your heel is past the narrow ankle point, your foot should pop into the hosen for a smooth, comfortable fit.
