I wanted to share some photos of a couple of completed blankets. I finished them with a round of hdc (half double crochet). In the next round, I evenly spaced 3 dc (double crochet) -- 6 dc, ch1, 6 dc in each corner. I repeated the shell pattern around with various colors, then finished with another round of hdc. I was going for a fun, random, colorful way to tie everything together, while using leftovers as much as possible.
It's interesting how a border and edging can change the look of a blanket. It's always helpful to see how different options look before you commit to one yourself. I hope these are helpful to you.
From the leftovers of my uncle's blanket: