Just the other day, I made a visit to my mom's friend's place to talk about some stuff going on with me. I hope that by typing this and everyone's reading, it can answer questions that you thought about.
We started it off talking about nightmares. I had nightmares every night after I started meditating. The one we focused on was a reoccurring nightmare. The advice given to me was this: The first was when meditating, try to have the dream come and communicate what it wants to tell you in a way that makes sense to you - like an email, writing it on paper, etc. The second she said was "to turn it into something funny." As soon as you get to the scary part of the dream, turn it into something you find hilarious. The third was to understand when you are dreaming (called lucid dreaming), and when you do that, you can choose not to do what made the scary thing happen.
The next thing we talked about was Precognition and Clairvoyance. I mentioned that I knew some things before they had happened and had dreams that came true. She told me to experiment with what I was feeling about the time where I knew what was going to happen, and write it down. Eventually you would know what feeling represented which event. With precognition, she told me about the same thing - write down the dream, and if it happened, you would write down when it came true and what exactly happened.
I hope I was of help to everyone, and if anyone has any extra advice on these subjects, I would love to hear it (I will most likely need some help with things like this in the future)!