The rest of his hair is filling out but not getting too out of control, so we don't think he needs a trip to the barber yet. Instead, I used my sewing scissors to snip off the back and then trim around his ears a little bit.
It went really well, because we never sat down to focus on it. The tail got snipped while he was digging through the bathroom vanity. The hair around the ears was while he was sitting on my bed looking at a book. Guess we're set for another 6 months! :-)