How to recognize Dream Signs?

Well I've started noticing some common Dream Signs in my dream.

Firstly, alot of my dreams (at least 2 a night) involve my school, and I graduated 2 weeks ago and never have to go back there, but I never think about that when I'm walking around my school. How can I teach myself to realize that its a dream when I am inside my school, because theres no reason I would be there.

Infact, last night I have 5 dreams I can recall and 4/5 of them took place in my old school.. kinda strange.

any tips

Oh, try thinking about it and then doing the RC, simple.

Well, try doing a RC everytime you see a school-related thing.
A pen, a notebook, books, school news on TV, among other things. Try to remember objects that appears in your school dreams, and do a RC when you see them.