I've finally finished the blanket (you can see the start of it here)
I added a ribbon tag on each square (2 on each of the corner ones) and backed it with a spotty fleece. To keep it stable I machined around each round.
It was complimented by 2 taggie cushions.
It has been well received and this has given me the confidence to seriously think about making them "off-the-peg" to sell.