How to Crochet a Puff Stitch
The crochet puff stitch (puff st) is aptly named because it gently puffs up into an oval shape. Puff stitching adds great texture to crocheted fabric. To crochet a puff stitch, you half-close several stitches worked in the same stitch and then join them together to finish the stitch. Try your hand at making a 3-double-crochet puff stitch.
Yarn over (yo), insert the hook in the stitch, yarn over, draw the yarn through the stitch, yarn over, and draw the yarn through the 2 loops on the hook.
One half-closed double crochet is complete, and 2 loops remain on the hook.
In the same stitch, repeat the preceding step twice.
You should have 4 loops on your hook.
Yarn over and draw the yarn through all 4 loops on the hook.
One 3-double-crochet puff stitch is complete.