There are many breathing techniques (e.g., deep breathing, holding breath, noticing breath) that reduce anxiety and help survivors cope with flashbacks. Many examples can be found on the Web. The link below is an example of three deep breathing exercises to reduce anxiety.
There are many grounding activities that can help survivors cope with flashbacks. These exercises aim to bring the survivor into the present moment.
One common exercise is called 5-4-3-2-1: You teach the survivor to notice FIVE things s/he can see; FOUR things s/he can touch or feel on the skin; THREE things s/he can hear; TWO things she/he can smell; and ONE thing s/he can taste.
Survivors discuss their mental health issues in these videos hosted by the Center for Survivors of Torture at AACI in San Jose, CA. The refugees come from Eritrea, Ethiopia, Viet Nam, Iraq, Iran, Afghanistan, Burma, China, and India. The videos are in both their home languages and translated into English.