I recently went on a yoga retreat in Fiji at Daku Resort and the owner very kindly organised for me to visit a village to sit with the women and weave a traditional Fijian mat.
The material was pandanus (known as voivoi in Fiji) leaves which are so strong – strong enough to walk on for years – so the collection and preparation of the material is extensive. They are boiled, dried in the sun, smoothed out by hand (using a file – pictured), split into strips.
The weaving was quite complicated, but once you got into the rhythm, it became easier. It was such a wonderful experience.
A more detail description of this is on the Daku Resort blog.