Here’s a technique I use when I knit double-sided blankets. Instead of knitting the sides separately, I knit the second side and attach it to the first as I go.
This is kind of an Intermediate level technique. Feel free to modify as needed.
To begin, knit one side of the blanket, the full length, binding off the end. You do not need to bind off, however, I find it makes a nicer, more consistent edge if you pick-up and knit along the bottom edge of the blanket to start the second side of the blanket.
Here’s where it can get tricky.
With the second right side facing, working into the edge of the wrong side of the first blanket, pick-up and slip a stitch onto the left needle:
K2tog (knit two together) and continue the right side of the second blanket to the end:
When you’ve reached the end of the row, turn, and pick up and knit a stitch on the edge of the right side of the first blanket, taking care to skip one row to allow for the row you just completed:
P2tog (purl two together), continue the row to the end:
Continue starting each row as above, remembering to skip a row when you pick up the stitch at the beginning of each row. (Confused? Sorry. If you have any questions, please post below and I will try my best to answer them.)
When you have reached your final row, you can now knit the blankets together and bind off the edge.
Slip a stitch from the first blanket onto the left needle. K2tog.
Slip another stitch onto the left needle. K2tog and pass the first stitch over the second stitch in the regular bind-off fashion.
Continue to the end of the row and bind off. Hide the end and you’re done!
My apologies for the inconsistency in the photos, as they were taken at different stages in different lighting.