I'd Rather Be Lucky, Though

According to research, appearing intelligent is not too difficult to pull off if one practices certain behaviors [bold added]:

They include showing self-confidence, speaking clearly and smoothly, and responding thoughtfully to what others are saying, research shows. And put away that phone: One of the strongest and most accurate signs of intelligence is looking at others when you are speaking to them.

(Psychology News photo)

Note, however, that the aforementioned are social signals that don't necessarily correlate with the mathematical and pattern-recognition intelligence that is highly valued by many who live here.

The type of personality that likes to dive deeply into a computer program often makes a poor salesperson for herself as well as her company.

We're probably overthinking this: just wear eyeglasses.