It's already been said by Richard here but as this point yea, nothing much you can do to fatten your buds besides letting it live out it's life cycle.
I would definitely recommend topping and LST for your next grow though. I was unsure at first (I mean come on chopping of the head of your plant, ARE YOU CRAZY!?!) but my plants recovered from topping so fast I even super cropped this time around and they have all recovered hard and fast!
I can't wait to see those beauties you have posted finished up though. Even for untrained plants they look really great so nice and tall.
What wattage light are you using? Also are they in your water heater room? I love it.