Well every time you become lucid can be different depending on the situation in the dream, and your frame of mind. Sometimes it doesn't take much thought at all to realize it, sometimes it takes more. It is of course good to question your settings and the events taking place. But I'd say if you're thinking about doing a reality check just do it, even if it ends up being a quicky because you never know. I've had a lot of situations in dreams where I thought maybe I should RC but I was into what I was doing in the dream and thought I'll RC in just a second after this, but then totally forget about it... Then wake up going grrr. lol

Something I like to say to myself is where am I and what am I doing? Because usually in my dreams I'm in an abnormal place involved in an abnormal activity. And even if in the dream it feels like a familiar place it's usually not right, work setting home setting almost always different or blended together with other places. So I try to stay aware if anything is weird or abnormal about where I'm at or what I'm doing.

I try to to keep the thought, awareness, and question on the mind as much as possible to get myself to think about it in dreams then throw the standard RC's in there too whenever I can, or if something seems weird. I always recommend practicing your favorite RC in dream even after becoming lucid so you get used to doing them in the dream and are familiar with how they work and feel in your dreams.

Today in a nap I recognized a talking wolf as a dreamsign (the fact a wolf was talking) But woke up in the middle of trying to reality check to find out if I was really dreaming. But I felt pretty aware, I was like OMG that wolf is talking obvious dreamsign reality check lol. But as mentioned woke up trying to RC too bad.