Increasing a border

I want to make a blanket and then add a border but I don’t want to crochet it because it kills my wrist. The pattern is a multiple of 2 plus 3–so my question is how many should I increase on the corners since I want to make the border in the round ( I want to use “net to the right” stitch pattern)? :??

You need to do a double increase at the corners. Either k1, yo, k1 in the same stitch, or kfb in the st before the one in the corner, then kfb in the corner stitch.