Sock patterns for Rowan 4ply

I have about 648 yards of Rowanspun 4ply in grey and the same amount in a sort of bottle green colour.

I was thinking of making socks for christmas presents, but would like to do something a little bit interesting. I have only made one pair of socks before top down and on DPNs using silvers sock tutorial, so dont want anything to tricky!

any ideas?

Thank you.