Silencing the mind is a well known Buddhist meditation technique that I've used for many years. But I'm not sure how effective it is for LDs. It encourages mental discipline, the ability to choose one thought over another, or to choose not to think anything at all.

A useful practice is to meditate at the end of the day, just before going to bed, to review the events and problems of the day and try to bring closure to them. That way you don't have so many thoughts pulling at your attention as you go to sleep. You allow the mind to settle down so it is relatively quiet as you fall asleep. However, that may not be enough.

A LD teacher called Peter Fellowes recommends a technique that he calls "dreamgate scouting". What you do is watch for HI like a military scout in a foreign land and report back to 'headquarters' whatever you see. You maintain a running commentary, an inner dialog, of whatever images appear. You actively self-talk your way through to lucidity. I tried this a few times several years ago and got a couple of WILDs from it, so I may try it again.