I don't know how long you have been keeping a dream journal, but that really helped me. My dreams seemed to be kind of bland, but once I got into the habit of remembering and writing them down, my brain was like "Oh! This is important to you!" And I started having better recall (and found out that for the most part my dreams are not bland, my recall just sucked).

Melatonin also helped me have some of the most vivid and colorful dreams in my life, but I built up a tolerance really quickly. Something to keep in mind.