ch4, join with a slip stitch to 1st chain.
round 1: Insert hook into ring yo and and draw up a loop, yo and draw through 2 loops on hook, chain 2, 2dc in ring, ch2, (3dc, ch2) in ring 3 times. join with slip stitch to top of 1st chain 2.
round 2: insert hook into last ch2 space made, yo and draw up a loop, yo and draw through 2 loops on hook, ch2. (3dc, ch2, 3dc) in next corner ch 2 space repeat * to * 3 times total. In last ch2 corner space work: 3dc, ch2, 2dc join with slip stitch to top of 1st chain 2 or round (this makes your chain up the last DC in the round)
round 3: insert hook into space where you just joined, yo, draw up a loop, yo, draw through 2 loops on hook, ch2, 2dc in same space. 3dc, ch2, 3dc in next ch2 corner space and each corner space there after. 3dc in spaces between 3dc clusters on previous row. after working last corner space slip stitch to top chain from beginning of round.
round 4: insert hook into space just created, yo, draw up loop, yo, draw through 2 loops on hook, ch2. Work groups of 3dc between each space on previous row. ON corners work 3dc, ch2, 3dc in each ch2 corner space. In last space work 2dc and slip stitch to the top of your ch2 from start of round.
See, every other round you are chaining up and that counts as the 1st dc of your 3dc group. than on the other rounds your chain up counts as your last DC of last DC 3 group of round. This I feel hides the “seam” best. your seam also stays centered along one side. I devised this after many yars of trial and error and not liking the way my grannies looked.
I only use chain spaces on the corners.
I think that inserting the hook and creating a stitch right on the 1st one also helps hide the appearance of the traditional ch 3 at the start of the rounds.
There are other ways to beef up your starting chain if interested in that as well.
I worked a grannie and wrote down each step as I went to make this post ☺
Here is the grannie I made for this post. the seam runs up towards the top.