Method used,

CO (or Pick Up) 49 stitches,
CDD to create the mitred square
knit all stitches on right and wrong side, purling only the CDD stitch on the wrong side.

Finished on 25th June 2016 with a total of 224 squares.

I was going to do an icord edging around the blanket but decided not to do that incase I decide to come back and make it larger at a later date. For now it is a perfect size for the sofa.