I had embroidery canvas that I had bought some years ago with vague intentions, which came handy. So I started, with a ball of yarn and a darning needle.
Rya technique is fascinating, and actually this is more or less how Oriental rugs are made, only the pile is of course much shorter. It took me three evenings to finish this small square. For a first try, I think it looks fine.
The other side gives a better idea of the technique:
You make a loop and then you make a knot, and another loop and another knot, until you have made a row. Then you cut through the loops. It takes a long time, but I wasn't in a hurry.
Apparently, these rugs were first used as blankets, imitating animal skins, with the pile down. Decorative rugs have the pile up, and you can make various patterns with yarn. I really enjoyed making this rug, so I will definitely make more.
Here it is in its environment: