Last night, I tried to MILD. For my phrase I chose "I will recognize the next dream sign I see." I practiced it in my head during the day as well, just to make myself familiar with it. When I go to bed, I usually sleep on my stomach, but this time I decided to sleep on my back. (The reason is because when I fall asleep on my stomach, I wake up in the middle of the night with trouble breathing because I've been putting pressure on that spot for too long. I didn't want to ruin my MILD by waking up again, so I decided to sleep on my back. It wasn't uncomfortable either, after a minute or two I was fine.) So basically I just lay there motionless and repeated my phrase over and over again in my head, while I let my usual thoughts flow. As I felt myself lose consciousness, I tried to do visualize a dream scene, but for some reason I can't visualize well on my back. So I just kept on repeating the phrase to myself and tried to lie still as best as I could. After an hour or so, I realized that I wasn't getting anywhere, and that if I keep it up much longer, I would lose sleep. (I didn't get a good night's sleep the night before, and didn't want to spend too much time awake.) So I turned over on my right side and just lay there like I normally do. I even stretched my muscles a little. When I was still again, I began to feel this strange heaviness in my muscles, almost like SP but not quite there yet. Then I saw this really vivid image right before my eyes (I'm not sure if it was HI, or an actual dream beginning.) I tried my best to hold on to it, but I eventually lost concentration and opened my eyes. So I went to sleep normally, and had a normal night.

Any thoughts of what I might be doing wrong here, or did I just get unlucky that time? What's the difference supposed to be between a MILD and a WILD?