How to get rid of nightmares?

I am bad for having nightmares, I don't drink/eat before going to bed, and I usually don't sleep for extended periods of time, maybe 20 minutes to half an hour at best, but I still manage quite a bit of sleep occasionally, like on my nights off, since I work 8 p.m. to 8 a.m. and yes, I used to have them before I started working nights. the nightmares are not recurring in any way, they are just random and come every night. I just laugh them off but they get annoying, since I always wake up with a migraine. Anyway long question short, how to stop nightmares