Definitely not an expert, but maybe you shouldn't be trying too hard. Don't focus on every detail. Relax every part of your body. Tense your muscles in your hands for about 20 seconds, then release, then your arms, then your shoulders and so on until you are completely relaxed. Clear your mind, just stare at the back of your eyelids and try not to think about anything, if you find your mind is wandering just stop and redirect it at nothing. Focus on the imagery that comes and goes, don't focus on the images itself, but let them come and go. If I didn't help you, Stephen Laberge has a book Exploring the World of Lucid Dreaming, there are lots of relaxation techniques and others to help you become lucid. Look up the 61-point relaxation technique. Hope this helps a little. This book really helped me a lot, easy to understand. Good luck.