A Nerd Wars friend over at Ravelry asked for more specific instructions for making the cozies, so I'm going to try & write it out here.
I used 2 different yarns, KnitPicks Swish DK (123 yds./50 gm) and Noro Silk Garden worsted (100m/50 gm). Because of the difference in the weights of yarn, there are 2 different patterns, so I will put the worsted info in ( ).
This cosy, in either weight of yarn, fits a small, 20 oz tea pot (mine were from Republic of Tea).
Hook size that I used: E/4/3.5mm (G/6/4.24mm).
The cosy begins with a crocheted band that is slip-stitched together into a loop, then the shell stitches are made along the side of the band. This solves the problem of a crocheted cosy not being stretchy enough to fit over the tea pot. Here's what it looks like at the bottom:
Next row: Single crochet in back loop only across row, chain 1, turn.
Repeat this row until you have 56 (48) rows.
Put foundation chain together with row just finished, making a loop (make sure it's not twisted). Working with foundation chain in front, make a slip-stitch through a foundation chain & back loop of next stitch to be worked. Continue across row, end with a chain-1, cut yarn with a 6"-8" tail & pull through to fasten-off.
Body of cozy, first side:
Row 1: [RS] Begin where you slip-stitched the band together. Make a sliding loop on hook & sc into hole to left of slip-stitched row if you're right-handed or right of slip-stitch row if you're a lefty. If you look along the band, there is a series of bumps (made of 2 rows of sc). In the first bump, make a 5-double-crochet shell, then single-crochet in the next bump. Repeat this until you have 7 (6) shells, ending with a sc. Chain 3 & turn.
Row 2: [WS] Double-crochet in the same sc as chain-3, single-crochet in the middle stitch of the next shell, *5-dc shell in next sc, sc in middle stitch of next shell* repeat to the end, ending with 2 dc in first sc in row below. Chain 1 & turn.
Row 3: [RS] Sc in first dc, *make shell in sc & sc in middle stitch of shell* repeat across, ending with a sc. Chain 3 & turn.
Row 4: [WS] Repeat row 2.
Row 5: Repeat row 3.
Row 6: Repeat row 2.
For DK weight yarn, make 2 more rows (8 total), fasten off.
For worsted weight yarn, stop here & fasten off.
Second side of cozy:
Row 1: [WS- shaping is reversed for 2nd side of cozy] Make a sliding loop & fasten yarn with a sc in hole on the other side of the slip-stitch row on the band.
Work the second side as the first, but, as mentioned in row 1, you're starting on the WS & will finish on the RS, which will allow you to keep going when you've finished the second side. In other words, after row 8 (6) do not fasten off.
Top of cosy for DK weight yarn:
Round 1: [always on RS now] Pull up a loop in sc just worked, and another one in first sc on the first side of cosy, bridging the gap, sc these stitches together. *Make a 4-dc shell in each sc, sc in middle stitch of each shell* repeat around (repeat bridging at other side of cosy by pulling a loop up in the top of each ch-3, sc together), end with slip stitch in first sc- 14 shells. Chain 3 & turn.
Round 2: 1 dc in sc, *sc in 2nd dc of 4-dc shell, 3-dc shell in next sc* repeat around to beginning, 1 dc in same sc as ch-3, slip stitch to 3rd chain of ch-3. Chain 1 & turn.
Round 3: Sc in in same place as ch-1. For this row, only the shells will be worked in (this decreases the top). *Make 5-dc shell in middle stitch of next shell, sc in middle stitch of next shell* repeat around, finish with a slip-stich in first sc. Chain 3 & turn.
Round 4: 1 dc in same place, *sc in middle stitch of next shell, 3-dc shell in next sc* repeat around, end with 1 dc in same stitch as ch-3, slip-stitch in 3rd chain of ch-3. Chain 1 & turn.
Round 5: This round also only works in the shells. Sc in same place as ch-1, *work 5-dc shell in middle stitch of next shell, sc in middle stitch of next shell* around, end slip-stitch to first sc. Chain 3 & turn.
Round 6: 2 dc in same stitch as ch-3, *sc in middle stitch of next shell, 5-dc shell in next sc* around. End with 2 dc in same sc as ch-3, slip-stitch to 3rd chain of ch-3. Chain 1 & fasten off. This cozy ends with 4 shells.
Weave all ends. I block the cozies by soaking them in warm water, rolling them in a towel, then placing them on the tea pot & setting on a heating vent to dry.