How to Knit Bobbles
You make bobbles (see the following figure) by increasing several stitches in a single stitch and then knitting back and forth on them before binding off, creating a knob on the surface of the fabric. The more stitches you increase in a single stitch and the more rows you work on them, the larger the bobble.
Note: MB = Make bobble: Knit into the front of the stitch, then the back, then the front, then the back, and then the front one last time, and slide the old stitch off — 5 sts in 1. Turn your work so that the WS is facing you (the stitches are on the LH needle). Purl the 5 sts. Turn the work around again and knit the 5 sts again. With the tip of the LH needle, pull the second stitch over the first and off the RH needle. Repeat with the third, fourth, and fifth sts.
To create a bobble:
Cast on a multiple of 6 sts, plus 5 sts.
Rows 1 and 3 (RS): Knit.
Rows 2, 4, and 6: Purl.
Row 5: K5, * MB, k5; rep from * to end of row.
By knitting on the RS and WS of the bobble, you make a textured garter stitch bobble. For a smooth bobble, purl the 5 stitches when the WS of the bobble is facing you.
If things start to feel tight as you work into the front and back of the stitch, insert just the tip of the LH needle into the stitch. After you wrap, however, be sure to bring your needle far enough through the wrap that the new stitch forms on the thickest part of the needle.