By request, I have been asked to create a tutorial for how to make a braided dh rug. The basis of the rug is from a book by Reader's Digest called "Complete Guide to Needlework", I just adapted it to what I thought would be dh proportions.
First of all, decide what shape of rug you would like and the approximate dimensions. What follows is for an oval rug, but I'll add a note about circular rugs at the bottom.
Start with three colours of embroidery thread, the usual 6 strands each that it comes in. Cut a piece of each colour to about the length from fingertip to fingertip. Don't worry if this turns out to not be enough, because it is easy to add more.
Make a knot at the end of the threads.
Attach ends to a firm surface in order to provide some tension.
Start braiding (left over centre, right over centre, left over centre, etc.), trying to maintain an even tension.
Continue braiding until you have a lenght of braid just longer than (lenght-width) of the final size.
Continue braiding until you are back to the location of the knot, then do 3 more round turns.
Then continue braiding until you have at least 6" of braid done. At this point, you can start to sew the braid into a rug, or just continue braiding until you reach the ends of the threads.
To start sewing the rug together, start from the knot, then gently bend the braid where you did your 3 turns. Taking a needle and thread, start sewing the two sides together with small stitches, making sure to keep the braid flat. (If done properly, you will not see the thread from the front side.)
Before going very far, we will have to deal with the knot. I put a small amount of white glue on my finger and rub it over the knot and the beginning of the braid, then leave it to dry. Once dry, cut the knot off and the end threads should remain together. If you are worried about the ends unravelling, you can always add another dot of white glue once you have sewn more of the rug together.
Continue sewing the sides together, bending around the end where you did your second set of 3 turns. Then just continue sewing around and around, making sure to keep the braid flat. The right side will look like the next photo (note that the yellow thread should not show - I was doing this quickly and didn't notice it until after I had taken the picture.)
Continue braiding and sewing until you have a rug of the desired size. When finished, just make a knot, add some glue, and cut off the knot once the glue dries, then sew in or tuck the ends under the rug.
If you run out of thread before you reach the size you want, or just want to change to another colour, just use a dab of white glue to join the two ends together, making the smallest bump possible. If you have to add more thread to all three strands, just stagger them so that the bumps are not all at the same place. They will not be very noticable anyway.
Note, if you want a thicker rug, just use three strands of something a bit thicker than 6-thread embroidery thread.
For a circular rug, although I have not done one myself yet, start the same way with the knot, then do enough 'round turns' so that the braid turns in on itself to form a small circle (the book suggests 6-12, depending on the thickness of the strands). Glue and cut at the knot, then continue with the normal straight braid until the desired size is achieved, sewing in a circular form instead of an oval.
Good luck and happy braiding! ;)