The trick that works best (for me), when you feel your are going to fall asleep, keep repeating, in your head, that you are are sleeping but you are awake. It took me a month at the time to get some results; after half a year it went mostly automatic. After that I have been able to do it without effort.

It takes patience though: the first 15-20 times you will likely just fall asleep and remember nothing.

Outer body experience (OBE) books, although nonsense mostly, usually have very thorough guides; I used one because I was convinced that what people call OBE is actually lucid dreaming and I was right. You can train yourself with those books (the one I had mostly had the above trick) and once in a while you will sink through your bed and hang on the roof in the room below or you ‘visit friends’ etc; obviously you are just dreaming but it is fun. You are awake enough to realize what is going and to manipulate the situation.

Not OP. This can get you going: https://www.reddit.com/r/LucidDreaming There are very simple tricks that can help, from what I understand. E.g. you can sleep with one leg outside your blanket and also writing down what you dreamt and reading it before the next day’s sleep.