There's been a weird thing lately. I'm by no means a every signle night level guru, but I tend to have them on successive nights and still relatively often. So lately I've been thinking I've found the key to success, because there is a seemingly very direct connection between the content of LD and an activity I've done before on that day. Be warned that this is based on a small sample because I'm just too excited to wait until there's more data, but this arguably applies every time someone says they've found the key.
So anyway, I've just been brainstorming ways to improve imagination/focus/whatever else would be helpful, and decided to just do "narration" sessions. Got the term from the tulpa subreddit btw, the guys seem to have some cool techniques over there, though they have to be adapted. You just start thinking of an object/situation, just pick something from recent memory if nothing comes, then start either somehow extending the scene/context or just follow the chain of associations that come up. Some call it daydreaming maybe? I don't have a vivid imagination or whatever, so it's not at all about getting lost in a wonderful world but rather about extreme focus to stay on the chosen path. Whenever I had a session, I would have an LD or something close to one involving some prominent "images" (not meaning just the visual) from it.
So here you go, maybe this is stupid, but it doesn't sound like a famous technique and it might work for right people.