So how do I use dream signs to induce lucidity and how exactly do you identify a dream sign?

I know the common directive is , whatever keeps reappearing in your dream and when you see it in reality, do a RC.

Well I have done that extensively to no avail, so I would like a more detailed answer.

For example, I frequently dream about being in a city a few hours from my home town. I dream about my brother and I dream about being on vacation a lot too. There really is no one dream sign that comes up more than others. I have other dream signs that also come up.

So the questions is how do you actually get a dream sign to make you lucid and why do the same dreams keep happening. Is there some relevance to it all?