I got these basic instructions from Attic24’s blog for her Granny Stripes Blanket and edited them slightly so they are easier to read and are in American crochet terms. These instructions are for changing colors every two rows. I only used one color for my Granny Cozy pictured, and then used another color for the trim. (I’m not sure her instructions about the multiples of 3 are correct. Mine never work out right. Whatever. You’ll figure it out. Just undo some if you have too many. Math is not my bag. Counting is hard.)
Measure the bottom part of your glass or cup. Beginning chain should be long enough to fit around the bottom of your cup (in multiples of three). It will still fit the wider part of your cup if you use a yarn that stretches a bit. I used Hobby Lobby’s ILTY and an I hook, but you can use whatever you wish.
Chain appropriate number for your cup size (in multiples of three).
Row 1 :: Work 1 sc in 2nd chain from hook. Continue working sc into each chain till the end. Turn the work.
Row 2 :: Chain 3, then work 1 dc into first stitch. *Skip 2 stitches, then work 3 dc (dc cluster) into next stitch*. Repeat between ** 4 more times, skip 2 stitches, then work 2 dc into last stitch on row.
You should have a row that begins and ends with 2 dc, and has 5 dc clusters in between. Turn.
Row 3 :: You'll be working out of the spaces between the dc clusters of the previous row. Chain 3 then work 3 dc into 1st space between clusters of previous row and in each space across previous row. To finish the row, work 1 dc into the top stitch of the ch-3 made at start of previous row. Fasten off.
Row 4 :: Tie in your new color...knot the two yarns tightly together, leaving ends to darn in after. To begin, insert hook through the very first space of the previous row (between the last dc and the previous dc cluster). Draw the new yarn color through to the front, ch 3, then 1 dc in same space. Work dc clusters into all the spaces across to last space, then work 2 dc into the final space. Turn.
Row 5 :: Chain 3, work dc cluster's in all spaces across to end, working 1 dc into the top stitch of the ch-3 made at start of previous row.
Repeat rows 4 and 5, working two rows for each color. Fasten off leaving a 5-6-inch tail for joining your rows together later.
Trim as desired. I joined my trim yarn with an sc between dc clusters, (ch 4, sc in next space) around; fasten off.
Whipstitch cozy together using the 5-6-inch tail of yarn you left at the end of your last row. Finish off.