Well, this might not really be allowed in a true DEILD, but what I normally do is review the dream in my mind subvocally, like I was telling it to somebody. You don't have to move or write anything down to do this, but actually putting it into words in your head and telling it in story form -- even without saying it out loud -- really locks it into my brain, and I can then remember all of them even if I wake up and go back to sleep several times.

But like I said, it might be too much mental activity for a true DEILD attempt.