Every time I try to DEILD, nothing happens. I’ve already trained myself to stay still when I wake up naturally, or when my auto-stop alarm goes off. I visualize where the dream left off, or if I can’t quite remember, I imagine a new dream scene. My body feels numb, but soon, the feeling goes away. After about 2 minutes of lying there and nothing happening, I just give up. Help?
It might take you a little longer to fall back asleep. Perhaps you are more awake than you want to be so it’s difficult to fall asleep again. Don’t give up, just relax, keep focusing on the dream scene, and do your best to fall back into the dreamstate.
Remember that your goal is to stay aware, not awake. You’re going to watch yourself sleep, but how can you do that if you stay awake? When you give up you’re actually falling asleep but throwing your awareness away.
About staying still, don’t take it so seriously. I’m not saying you should move, I’m saying you should let yourself fall asleep. When someone is going to fall asleep he stays still until he passes out. You’re just going to take the passing out part out of the procedure.
Relax. You’re trying to sleep so that’s what you’re going to do. You don’t have to visualize the dream scene, because it usually just manifests itself, for me at least. But if it works for you then do it.
EDIT: It takes a while to get the hang of it, don’t be discouraged.
Same thing happening to me, but i’m assuming it just takes practice and patience to get it right. I’m just going to keep trying it until I get it. 
I prefer writing because I can write immediately after waking. I also like to sketch interesting things that are really hard to describe, like this weird bridge I dreamed of.