The U-method.

The U-method derives its name from the U-shaped way the rope is applied to the arms.
It's a brilliant way to bind things together, as long as they are not parallel.

1/ Lay the middle of the rope over the arm at the top, then under the lower arm, on either side of the upper arm. Now you cross the ropes over the wrist of the upper arm, and continue round and round, until you've got 3-4 'lines' next to one another. 
There's no need to tighten the ropes now, we'll get to that later on.

2/ Cross the ropes, and pull them around the ropes around the wrists a few times.
Now you tighten the ropes, and this effectively locks the arms in the bondage.
(And if your partner was giggling over the loose bondage you were fumbling with, that'll stop now ).

3/ End the bondage by locking it all together with a reefers knot. You might want to tie the knot, where your partner cannot get at it..!

Now use the remaining rope, to tie your partner to a bedpost, or...

If you tie the ankles up this way, it will be difficult to put the knees together..!