To knit a circle, start with a magic ring or small string. For the magic loop, wrap the yarn around your finger, pull a loop, and sew a loop. A series of single crochet stitches are knitted into a stitch, usually starting with six. Pull the tail to tighten the loop. In the next round, increase the number of stitches by making two single crochets in each stitch. For a flat circle, continue increasing at the same rate for, say, 6 stitches around it. This technique is useful for making hats, coasters, and other round items.