First of all, sorry for the clickbaity Title. I’ve been interested in lucid dreaming for years now, and I have actively tried to lucid dream on and off for most of those years. However, I have not had much success, other than improving my dream recall on some nights. I think that this is due to two problems. 1, I have a hard time focusing. I try to focus on staying awake, but my mind will wander, and the next thing I know, I’ll go through the night without being lucid. 2 (and this one is a bit tough to explain), I seem to not be able to dream about the things I think about. Let me explain: People talk about having certain signs in dreams, things that often pop up in theirs. I have had reoccurring themes in my dreams as well (strange libraries are one big one for me). However, when I acknowledge a dream sign, my mind somehow refuses to incorporate that into a dream. Signs will only appear when I have not consciously thought of them recently. Does anybody else have similar problems, and if so, have you found anything that helps? Thank you, and happy Lucid Dreaming 
Hello @Kiito 
I don’t think your problems are very odd, I think they are common enough.
- Focus
You mentioned that you’re trying to stay awake. What exactly are you trying to accomplish? Are you talking about applying a specific technique and if so, which one?
The ability to focus one’s thoughts properly and not give in to distraction is one of the worst pandemics of the Information Age, I presume. We are constantly bombarded with news and things that demand our attention that we have little faculty left to pile it all up on a single item that we think we really should or want to. Instead we are squandering it left and right. I also get some horrible habits. As a general solution I recommend to reduce your smartphone time and turn off all nonessential notifications of any system that has the potential to distract you.
Whether you think I hit your problem or not, a technique generally useful for focus and dreaming is meditation. In fact I almost always meditate for a few minutes before I try an induction technique as I’m preparing to fall asleep. I’m not a master on this so I’m not good with specific advice. But there’s tons on the internet.
- Dream signs
I’m totally feeling with you here. I have several themes that should classify as my dream signs but they fail to make lucid because they are really elusive. I cannot theme to incubate them or predict when I would dream about them. I guess what this means is that they are simply not very strong dream signs. Dream signs work best if you dream about them regularly and encounter them decently often in waking life. Libraries I guess are at least somewhat plausible if you’re visiting such places often, or are visiting similar places like bookstores. I don’t have very strong acids for this issue sadly. I can think of these on the top of my head:
- practice incubation to make them appear more reliably (or just do MILD)
- keep looking for more and possibly more reliable dream signs until you have a good repository of dream signs that could trigger you
- increase your recall so you simply have more dream content
The last one is particularly effective if you only have very few dreams each week.
A different approach could be to try explicit induction techniques rather than relying on dream signs. Since DS tend to work very poorly for me I personally always thought DS triggered DILDs are overrated 
But this probably varies a lot among dreamers. As a very common and always useful advise, I suggest you try to increase your awareness during waking life. Take on your surroundings more. Observe (the external world as well as your interior one) and question. You know, things like „How did I get here?“, „What am I doing right now and does it make sense?“, these kinds of questions.