If you're interested in lucid dreaming (which I can say from experience is bucketloads of fun...an entire reality that you control!), a good way to get more vivid dreams is to stop smoking weed for a few days if you're a daily smoker. I always find doing this makes me remember my dreams better and they're much more detailed. For instance, I ran out of weed a few days ago and can't get any till this weekend, and I had a lucid dream last night. I can't remember what it was about but I do remember walking around the downtown area of some city and thinking to myself how realistic it looked and being amazed that my brain could come up with all of that detail, spinning the tires on each car realistically, coming up with each glimmer that reflected off the shiny sidewalk, designing the architecture of each building. It was incredible.