The National Library of Scotland and the Scottish Screen Archives have a wonderful collection of films about the Shetland Isles. Back in the 1930s, Jenny Brown made several films about the Crofters. One of which is called "In Sheep's Clothing".
This film depicts (silent) scenes of the men and women herding the Shetland Sheep, they can be seen gathering and then "rooing" sheep. There are also shots of the carding and spinning of wool and the women knitting to make jumpers and shawls.
You will have to go directly to the website to view the films, here is a link for you to get there:
Related films can be easily searched. I watched several. There is one that shows the washing and blocking of the finished shawls. I was amazed to see how vigorously the delicate shawls were washed and wrung before placing sticks in the ground on the open field for the blocking of the shawl. Very different from today with our blocking wires and mats and pins!