I have vivid dreams often, and one reoccurring dream. They are almost always in depth with a "story" kinda like a c list film with random props and tangents that lead nowhere. Its not always fun, I have had some that I can still see in my mind, as if it actually happened. Sometimes I wish I couldn't, having a vivid nightmare is terrifying.
back to the point, some people say to drink a lot of apple juice before bed (could just be a wives tale)