Getting at least 8 hours of sleep or more is of great help to me in dream recall.
Supplements are also a key in helping me with dream recall, as last night I was having trouble remembering anymore than fragments until I got up after about 6 hours of sleep and took about 6 grams of GABA with a ZMA capsule and a couple of Ginko Biloba, after which I had two very vivid dreams and then an image stream later.
Energy level, especially my sexual energy level seems to be a big key, as if my sexual energy is real high I usually wake up every 2 hours remembering dreams. Unfortunately lately it has been a bit low and I am having trouble even waking up during the night.