To achieve a perfectly rounded sock toe without “ears”, simply graft the toes with Kitchener stitch as follows:
STEP 1:
Insert the tapestry needle knit-wise through the first stitch on the front needle & slip that stitch off the needle.
STEP 2:
Pull the tapestry needle purl-wise through the second stitch on the front needle, leaving the stitch on the needle.
STEP 3:
Insert the tapestry needle purl-wise through the first stitch on the back needle & slip that stitch off the needle.
STEP 4:
Pull the tapestry needle knit-wise through the second stitch on the back needle, leaving the stitch on the needle.
Repeat STEPS 1-2-3-4 until 1 st is left of each needle. Slip these sts off the needles & pull yarn to tighten up the loops. Weave in the end on WS.
Here is a short video for your reference:
This tutorial features my Modern Heirloom Cable Knit Socks pattern.