On the ride home from the dojo tonight, my buddy said his dog helped him find the kyusho portion of yonkyo. He just started aikido recently. One night we started training yonkyo and he immediately recognized the kyusho application because his dog sometimes clamps his mouth around my friends arm and takes him to the ground in what is basically yonkyo...with the pressure point application. He has a giant sheepdog.
My dog does a really beautiful forward ukemi when it is pretend fighting with it's friend (a golden retriever four houses up the road).
Apart from that I didn't start to do good yonkyo until I stopped focusing on the pressure point and started thinking about just placing my body in the right spot and keeping the balance of uke on top of my hand.
It seems whenever I have truble with a throw or a lock I need to remember to move the tip of the sword instead of making the technique small. It usually helps a lot