Here is my two cents on dream clarity.
Last night I had a lucid. One where you just realise you are dreaming. This really hot girl I knew was standing next to me, and I had unfinsihed business from a previous dream. Unfortunately, I lost all clarity, the image went fuzzy and blurry and diffcult to make out, like being really drunk. Then it went black. There was nothing there, and I was on the verge of waking up. But I wanted it back, so I didn't get excited or disappointed. I just concentrated on willing the dream to return. After a few seconds, it did - it formed with complete clarity. And you can guess what happened from there
Anyway, it lasted about 2 minutes, becuase I was walking around looking for another girl (yes - the focus of my LD's are rather predictable.) The dream started to fade again, I tried to stop it but this time it didn't work. I woke up with a buzzing in my ears and sleep paralysis.
So basically, this just goes to show that if you don't get excited, frustrated, worked up, and don't lose hope, it is easier to maintain and re enter a dream. Perhaps a tip for other newbies like myself?