I think the key is to try not to assume anything before doing RCs. When I'm about to do one, I suspend my intuition for a moment and just honestly ask myself what should I do if this turns out to be a dream. Then I perform the RC, being prepared to accept and act on whichever result it happens to show. This has served me well since a lot of the time I'm actually quite surprised to discover I'm in a dream and not real life. Getting used to trusting the RC more than my own assumptions allows me to avoid “explaining away” the RC result in a dream and remaining nonlucid.

RCs in dreams seem to work better as confirmation tools for me than invoking lucidity in themselves. I usually start suspecting I'm dreaming by noticing something a bit weird, then I'll do the RC to find out what's going on. I think this is because my habit in waking life is to try to remember to RC (and be open to either possibility—WL or dream) anytime something seems just a bit off (even if it's not all that unusual), or I have a particular emotional feeling, etc.—whatever seems to occur commonly in my dreams.