I created this version of my shell block squares, with puff stitches added as a variation. This one is in a five inch finished size.
Abbreviations: ch = chain, dc = double crochet, ea = each,
sc = single crochet, st = stitch, sts = stitches, YO = yarn over (wrap yarn over hook)
Materials: about 1/4 oz. worsted weight yarn, US size H hook
Special Stitch: In this pattern, Puff Stitch = YO, insert hook in space between two shell groups, YO, draw up a loop, (YO, insert hook in same space, YO, draw up a loop) 2 more times, YO, and draw through all loops on hook, chain 1 to close the puff stitch. Note: If you want it to puff out more, you can do the part of the instruction YO and draw up a loop additional times to make the puff stitch thicker.
Special Technique: dc in space between two shell groups ... Instruction link: see photo how-to
Pattern Notes: Turn at the end of each row.
Gauge: 7 dc = 2 inches, 4 dc rows = 2 inches
Finished size = 5 inches square
Starting Chain: Leaving a length to weave in later, chain 16.
Row 1: sc in 2nd ch from hook, sc in ea ch across. (15 sc)
Row 2: ch 3 (counts as first dc), dc in ea sc across. (15 dc)
Row 3: ch 3 (counts as first dc), dc in ea of next 2 dc, skip next dc, 3 dc in next dc, skip next 2 dc, (dc, puff stitch, dc) all in next dc, skip next 2 dc, 3 dc in next dc, then skip next dc, dc in ea of next 3 dc.
Row 4: ch 3 (counts as first dc), dc in ea of next 3 dc, skip next 2 dc, 3 dc in space between next two shell groups, skip next shell, 3 dc in space between next two shell groups, skip next 2 dc, dc in ea of next 4 dc.
Row 5: ch 3 (counts as first dc), dc in ea of next 2 dc, skip next dc, 3 dc in next dc, skip next 2 dc, (dc, puff stitch, dc) all in space between next two shell groups, skip next 2 dc, 3 dc in next dc, then skip next dc, dc in ea of next 3 dc.
Row 6: Repeat Row 4.
Row 7: Repeat Row 5.
Row 8: ch 3 (counts as first dc), dc in ea of next 6 dc, skip the ch-1 that closed the puff stitch, dc in top of puff stitch, dc in ea of last 7 dc. (15 dc)
Row 9: ch 1, sc in ea dc across. (15 sc)
Outside Round: ch 1, then (working down the side of the piece), sc in end of first sc row on side, make 2
sc around post of ea dc along the side until you come to the next sc row at the end of this side, sc in end of that sc row, ch 2 for corner, sc in remaining loop of ea starting ch along bottom side, ch 2 for next corner, sc in end of sc row, 2 sc around ea dc post on that side, sc in end of sc row at end of this side, ch 2 for corner, then sc in ea sc across the top, ch 2 for corner, ending with a slip stitch in the first sc of this outside round.
End off, leaving a length to weave in. Weave in ends securely, weaving back and forth several times on the back of the square, working under back part of a number of stitches so that the ends will not unravel over time.