I know this is an old thread but I thought I'd add the one tip I got from my boyfriend's therapist: bi-pedal movement. Yep, walking.
It works to help get the two hemispheres of your brain working together again (just like EMDR does).
My boyfriend had an episode last week. He has complex ptsd and his "flashbacks" often take the form of panic attacks. His muscles will seize up and he will hold his breath or hyperventilate. After the entire thing has passed he is sore and barely remembers a thing. After a bad night full of nightmares (preceded by a fight) I found him on the couch, totally freaking. He knew to ask for help, so I talked to him and held him (supporting his weight – because he was wobbly) as we walked around the room a bit.
We've done this before, and even though the walking never lasts very long, he always says that it helps.
And thanks for the tip Amethyst. I am going to ask him to walk me through "safe place" next time. With bi-pedal movement, safe place and aromatherapy, I think we'll have a pretty good repertoire.