You have the data pins correct, but terminate all the wires in the connectors. There is no reason to not connect all four pairs, and several reasons why you should. Just do the other two pairs as you would a straight cable.
Good Luck It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com