A tip I really liked was this:

Throughout the day randomly stop and just take a look around you and take the time to really see in detail what is there. If you are the kind of person who is always going from point a to point b and always preoccupied...That'll transfer over to your dreams. So try, every once in awhile, to really just soak in what's around you. If you are at work take a look at the office and soak in how everything is laid out. How your desk feels. The color of the carpet.