I say “standing” because it will take more practice before I can walk and chain ply. Chain plying is a way to make a three-ply yarn from one single, much like making a foundation chain in crochet with very long loops. If my single ply is supported I like to make loops as long as my arms can reach, but if I’m holding the source yarn in one hand and the spindle in the other, I have to shorten the loops to maybe half an arm span. And it takes more concentration to keep the three strands under tension and unkinked, so standing (with an occasional ball kick) is about all I can currently manage.