Last night when I was dreaming I remember clearly thinking "this is a dream" So upon thinking that, how would someone go about doing a reality check? I understand you can look in mirrors and clocks but these items are almost never in any of my dreams.

I guess what Im trying to get at is that I can discover I am in a dream but how do I get my mind to perform a reality check? Just remind myself consciously before bed or what?

Thanks in advance