It's really not rocket science. It's nature art!
Find yourself a nice vine or twig or branch that has at least one V. I made my frame out of honeysuckle. I do not feel bad about harvesting a branch cut from the bush because Japanese honeysuckle is a brute. An invasive that just keep spreading through our native habitat and choking out our local plant biodiversity. And, it's more flexible when it's green.
I tied mine together into an arcing eye shape but you can leave it a Y or V shape if you prefer, or if you can't bend your branch.
Once the end is tied (or not), begin to weave the string of your choice from side to side, forming a continuous W, back and forth from one end of your loom to the other, wrapping it a couple times before moving on.
Then, go out in your garden, the prairie, a field, and gather a few stalks of in-season plants, flowers, and seed heads.
Weave them into your loom from the base of their stem pulling through so not to ruffle the foliage in the wrong direction.