In my last LD I did it before and after I became lucid. In a dream I was reading a book and in the middle of one of the words was letter in a different font than the rest of the text - in was capital "T". This made me remember that text is unstable in dreams and can be used as a reliable RC. So (well, not excepting that it can be a dream though) I looked away, than back, twice. I tried to find if anything changed in the paragraph I was reading - nothing did, even this weird "T" stayed on its place. I quickly thought that it may be misprint, but my own thought didn't persuade me, because at that point I already looked around and noticed that the place where I am only looks half-familiar - as if I've already seen it, but haven't been here before, like from a movie. So after that I did usual sequence of RC - looked at my hands, tried to push one hand through another, all fine, then I pinched my nose. After that I realized that I'm indeed dreaming and decided to look at the text again. Look away, look back, twice again. All stayed the same. I can't remember what was written though, my dream recall suck now
I don't even know how many lucids I've missed, because of this. But, I don't have that much of experience with all of that, it will probably be different in the future
I probably have written it wrong - numbers are the opposite - the seem to go crazy in the dream, but only after I accept it to be a dream.
Anyway it's complicated, but I can always rely on nose pinch, which I actually always do few times - the feeling is so weird it's hard to believe))