Recently I've beel listening to an audiobook by a teacher who's left Zen. One idea of his that I found intriguing was to sit with an inquiry.
I remember when I've had the clearest realizations, I was often intently asking 'What is this?' I think Lin Chi's "What at this very moment is missing?" is also a good proxy, although maybe too wordy. Sometimes, I just 'look, look, look'. There's just a probing 'what?' or 'Hmmm'. English doesn't have a word for the pure interrogative, but I think Japanese does.