My 4 yr old daughter has both nightmares and night terrors (which have happened in the middle of the day, while she was asleep in the van. While we were driving!! Holy crud, that was awful).
They seem to be getting better. I like all the above suggestions. A nice warm bath to unwind goes a long way, too.
We talked to her about hitting the `stop `button DURING the dream. I don`t know how much that has helped. I also taught her to sing a song if she wakes up afraid. We chose Twinkle Twinkle Little Star. We told her to sing it quietly to herself, and that way she will know that she is ok, it was just a dream and that she has control. It`s like a touchpoint for her.