I keep a dream journal next to my bed and write down even little scraps of a dream as soon as I wake from one. (yes even at 3am! some mornings it's hard to read what I wrote while half asleep!) Sometimes I get nothing but a vague feeling, or a word, or that it was about a particular person. I sorta mentally ask my dream-maker to show me more. Or, I tease around what I have in my mind during the day, and sometimes - sometimes - I'll get an "Aha that's what that was!" later in the day. I've had dreams that explain previous bits of remembered dreams too, I know this only because I go back and read through my dream journal frequently because dream work fascinates me!