River value bet?

got into a spot last night where i had second pair on the river, board was dry, heads up. opponent checks to me after calling flop and turn. i’m always struggling to pull the trigger on value bets in these spots, never sure if i’m just betting into better hands or if i can squeeze value from worse pairs. everyone talks about thin value but in the moment, i freeze up.

does anyone have a way they break this down in the hand? do you use player tendencies, bet sizing tells, something else? i feel like i end up leaving money on the table being too passive here. how do you approach river value spots with marginal made hands?