The crochet puff stitch is a decorative stitch that adds dimension, volume, and texture to crochet fabrics. It is created by working multiple yarn overs and pull throughs into the same stitch or space, resulting in a "puff" or "bobble" effect. Similar crochet stitches include the popcorn stitch and the bobble stitch.
To Complete a puff stitch:
[Yarn over and insert your hook into the indicated stitch, yarn over and pull up to working height] 2-4 times (depending on what the pattern calls for and/or how "puffy" you want the stitch). Yarn over and pull through all but 1 loop (2 loops now remain on hook). Yarn over and pull through the remaining 2 loops.
*Remember to consult patterns or tutorials of any specific pattern for possible custom instructions on the number of loops and other possible variations of the puff stitch.