I've had about 12 lucid dreams in total now (this is counting the little dinky ones that last 2 seconds (although I've had a few really good ones too)) and I've found that when I become lucid, my biggest difficulty is stabilizing myself and my environment. If I don't start out with complete control from the moment I become lucid, then it's basically impossible for me to clarify things. I've tried looking at my hands, but the last time I did that the whole dream started turning dark like someone was turning the lights out, and there was nothing I could do about it, because I knew that if I tried to will too hard I would wake up. I knew I was waking up anyway.
Another thing that happens is that I have a hard time keeping still. I'm always rushing around everywhere, and as a result I can't get a grip on the details of where I am, and end up losing lucidity quickly.

So I guess this post is kind of half about increasing clarity, and half about getting better control. Because if I had control, I would be able to make things clearer, and if things were clearer, it would be easier to get control!

Does anyone have any tips, or any links to tutorials that could be particularly useful?

Thanks!