I've recently been on a string of increased DILDs after being almost exclusively on WILD for a couple years. The DILDs almost always start with me thinking:

"If this is a dream, I should be able to..."

And then without completing the sentence with words, I perform a test of dream control, usually telekinetically pulling an object in the environment into my hand. Now to be honest, what's happening is more of a reality check to confirm lucidity rather than to trigger it. Nevertheless, I think the alternate sentence structure may be interesting.

More generally, the idea I'm developing is to use a "What if..." open-ended speculation (an example of counterfactual thinking) instead of a yes-no close-ended question (an example of propositional logic). My hypothesis is that counterfactual thinking may engage different mental faculties than normal logic, so that the action of speculation is less impaired (or at least differently impaired) while dreaming. The "what if..." challenges you to engage in some imagination to create proof of a dream, rather than trying to detect proof. Creating proof may be easier than detecting it.