A word to describe a subjective yet natural feeling about something
Solution 1:
The original post itself alludes to two perfectly good adjectives: intuitive and instinctive.
Googling "define intuitive" yields as the primary definition: Using or based on what one feels to be true even without conscious reasoning; instinctive.
"define instinctive": Relating to or prompted by instinct; apparently unconscious or automatic: "an instinctive distaste for conflict."
My sense is that intuitive implies some degree of certainty, even though one might not be able to present logical arguments that would convince someone else--or, at least, without more effort than one wishes to invest. Instinctive, on the other hand, seems to convey less reflection.
One might intuitively select pieces that will coordinate well when decorating a room.
One might instinctively react when one's child starts to walk toward a busy street.
Solution 2:
It's like an intuition.
How about intuitively?