|The non-working threads stuck down|
I found myself in this situation when working on piece of bead weaving. Having created a seed bead loop to attach the threads to a pendant I needed to keep the tension on the loop whilst working on the bead weaving for one side of the necklace. My solution - stick the pair of threads that would eventually become the other side of the necklace to the worksurface.
Once the beading was complete on both sides it was simple to hold the piece at my neck in front of a mirror and find that I needed to remove several pattern repeats to achieve the right length. I was quite relieved to have used tape rather than a crimp!
You can see the completed necklace here