Pay attention to what they do with their lower lip (more blood flow makes the lip darker, puff out and down), watch all the things your partner does outside of consciousness, with their lower lip.
Pay attention to the eyes- color, size of pupil, amount of tears, dryness, blink, where they look when you ask questions.
They eyes have a lot to tell you.
Pay attention and make sure both of you are working on the beginner level noticing before moving to intermediate skills of leading the partner. Some of these are easy to lead and others don’t fully lend themselves to that.
Make sure each of you is doing it.
Women tend to do better on these than do men, unless the guy has a job where this is important.