The best players will avoid trying to make an exploitative decision (e.g. guessing the correct level the opponent is thinking on), and instead make something approaching a game-theoretically optimal one (e.g. a maximally unexploitable strategy).
For example, if you're facing a big bet where you can only beat bluffs (e.g. all missed draws), but lose to any value bets (e.g. sets, straights, flushes), then you'll need to mainly be folding, but to avoid being exploitable you'll also need to call down with some percentage of these mid-strength hands (where the exact number depends on the bet size relative to the pot).
To decide which bluff-catchers you want to call down with, you'll want to pick hands that don't block any of your opponent's bluffs (e.g. you don't want to be holding the Ace of Spades on a flop that had two spades but a third didn't come by the river, since having this card eliminates a number of likely missed flush draws that your opponent might be bluffing with). In addition, you'll also want to pick hands that DO block some of your opponents value bets (e.g. your hand contains one or two cards that block your opponent from having straights, flushes, sets).
Naturally, calling down with the correct ratios is rather hard and only the best players can do so with any consistency, but it does remove the whole levelling guess work and reduces the decision to something you can reason about.