Hold your horses, where'd you get a loop of two strands?
Try taking a long strand of cord, it should extend from finger tip to finger tip. Then tie a locked sheep shank in the center (it's okay if it's off, that's actually good).
West country whipping is the method that Rat Man and a few others use. It's a nice touch, but if it's getting in the way, then let it go.
So just tie a locked sheepshank in the middle.
Here's a tutorial:
http://www.animatedknots.com/sheepshank/index.php?Categ=scouting&LogoImage=LogoG...To 'lock' it, thread the running ends through the loops. Look at the final step, the loops on the sides are very clear.
Then weave a strand through it. Under, over, under over. Keep it as tight as possible
After that tie a loop on one end, and a stopper knot on the other.
~fini.