There are many ways to calm a werewolf once he/she has shifted. But these methods are not normally tried by an outsider of the wolf. In fact, once the transformation has taken place it is ill advised to interfere with the actions of the wolf.
But the werewolf himself can take advantage of the methods if he can become lucid enough to understand the exact state that the wolf is in. The werewolf must realize that he/she has turned and must immediately take steps to try to calm.
This is a debated topic since many believe that the werewolf maintains control no matter what happens. But the fact is that many lose control and cannot maintain themselves. This is partly because of the adrenaline rushing through the body, which is normal. The heart starts pumping and the blood starts flowing, adrenaline kicks in quite rough.
To maintain the weighted one should do everything to become calm before an inevitable shift. Breath deeply, trying not to think of the impending change. Shift your thoughts to something pleasant, again, not the shift. Keep your limbs under control, shaky hands and shaky legs or feet need to be controlled. Focus. Focus on anything but the change, the transformation could change your life – positively or negatively.
There are techniques that I have not touched upon, but I am sure many of the werewolves or weighted ones out there will share their experience on how to maintain control.