This video from the USA says about itself:
Things to know when you provide hummingbird nesting materials
31 January 2016
If you are watching this footage, then I must say thank you for helping them out. It takes a lot of energy for them to find nesting materials.
Some hummingbird females are more experienced than the others. Those two took the easier route; they simply picked up the already pulled out ones and selected desired sizes right off the ground.
Just like you’d do with the feeders, hang the materials high enough so that cats can’t get to the hummingbirds. In this video where they were near the ground is a section-off narrow corridor that no other animals have easy access to.
If you have a bully claiming your feeders, hang the material away from the feeders so the females won’t be chased away.
If you want to reduce the probability of other species of birds building nests around your home and thus discourages female hummers selecting nesting sites around your home, try position the nesting material flush underneath a flat surface so only the birds that can hover, namingly hummingbirds, have easier time to get the material.
Hang the material so that it won’t be affected by the rain. Don’t forget to fluff it up before you hang it to make it easier for hummingbirds to pull it out. IMPORTANT: Please replace it every year! The material serves as a filter that traps pollutants and mold spores that will potentially cause respiratory illnesses. The illnesses may not become apparent until a few weeks later when the chicks have already fledged.
If you do happen to have a female built a nest near your home, please remove the electrical cords (such as Christmas string lights) so they don’t perch on them. Lead from the electric wires poses a real lead poisoning threat.
From the Cornell Lab of Ornithology in the USA:
Providing Nesting Materials: Dos & Don’ts
Birds’ nests are works of art, woven fibers and sculpted mud. Sometimes those gorgeous nests contain human-made materials such as cotton threads or plastic tinsel. Even your dog’s fur or a horse’s mane can be incorporated into a bird’s nest.
It is tempting to provide these easy-to-gather materials for birds; however, new evidence from wildlife rehabilitators suggests that caution is warranted when putting out nesting materials. Even fur and other seemingly innocuous materials can tangle and entrap adults and nestlings. In light of this new data, the Lab has recently revised its list of Dos and Don’ts for providing nesting materials to birds. Do your part and keep birds safe this nesting season!
Do provide any combination of the following: dead twigs and leaves, dry grass (make sure the grass is chemical-free), feathers, plant fluff or down (e.g., cattail fluff, cottonwood down), moss, bark strips, and pine needles.