Happy to explain as best as I can...
For me the idea came from old braided rag rugs....in the old days, some folks saved otherwise used up fabric scraps for braiding rugs...the fabric would be torn into thin strips, the ends would be joined (sewn together) as needed, and the fabric wound into a large ball...as these fabric balls accumulated they would be stored in a basket or box until there were enough to braid up a rug...
A long time ago I bought a basket full of some really neat old time woven material that was all balled up and ready to use for rugs...I started twisting that up and using it for horn straps but didn't like all the sewn joints....so these days I replicate the basic idea by purchasing a 2 yard piece of old timey looking fabric or ticking ...I cut it into narrow 1/2" wide strips as needed, and boil the strip in strong black tea to age it some....I remove it from the tea, wring it out under cold running water, and begin twisting the strip...it will shrink up because of all the twists, but I will either stretch and clamp it, or hang it with a weight to stretch it as it dries...thats it....however, that "balls of fabric in a granny basket" look is becoming fashionable again, and some antique, craft, and flea type markets are actually selling balls of new balled up fabric strips as decorations...they still need the tea bath, twisting and stretching, but would otherwise work pretty good I think...
Hope that explains it some and is a help...
tc