Try focusing on your surroundings. Pick out a couple things around you and focus on them. Walk up to them, look at them, feel them. Try and gather as much information as you can. Not only will this help stabilize your dream, but it will also help with vividness. If you're familiar with SAT or ADA, it's like these, only more intense and only for a few seconds at the beginning of the dream.

It may also be your recall; your dreams were actually vivid and you're just not remembering all the details. If this is the case, just be sure to keep up on your dream journal. Try writing down more details, as many as you can, and re-read it every once in a while. Your DJ is the foundation of your recall, so you don't want it to be lacking