In this timelapse video, you can see me carding cotton on 120 pt fine hand carders, creating cotton punis for spinning, then spinning and plying cotton yarn on a tahkli spindle.
In this video, Megan LaCore demonstrates plying two single-spun yarns together on a top-whorl drop spindle. Spinning two or more yarns together is a helpful and versatile technique that every spinner should have in their knowledge base.