Next, you yarn over and pull the yarn through both the loops that have formed on your hook in order to finish the first single crochet stitch. Now, your circle of yarn should start feeling more secure as compared to the beginning of the circle. As the loose end could still be easily pulled, make sure not to tug at it while you are working.
Add as many more stitches required for the design you may be working on. Do not worry if the ring seems too open, this is part of the process, and may get better by the time you reach the end.
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