Testing some threads from a fishing store
Don’t ignore fishing stores, there are threads there too! ^^
1. Superfine threads
Good for very fine-grained texture, for further objects like on pine branches, for extremely small architectural details (darker colors, not light)
2. Flat metallic threads
As you can see, it's nothing special if you use them to blend with other threads or pine needles.
They are mostly good for waterfalls, but I would also use them (green colors) for willow branches. In these cases, they will give a unique effect!