Well recognizing bluffs at poker is a fine arts at itself, you can't really explain this, you gotta learn to scent it by yourself, if you know what i mean. As
diadiavalik right said: notes is the king, and of course the type of opponent too. Let's say loose-aggressive player tends to bluff like 3 times more than tight-aggressive and 10 times more than a nit. The other good skill is "reading the betting story" properly. If you facing a raise, don't be in haste to insta-call your top pair, cause you are thinking someone is
bluffing. Better click on time bank and try to analyze how these hand been developed. Try to put your opponent from beginning on at some hands range and try to figure out how much percent of this range could really hit the flop, turn or river. If you can't figure out the hand which could fit that range and the bet doesn't seems to be logical, must be that he is bluffing you. "The story, that he
tells you by betting sounds like bullsh1t". It also very differs from one limit to another. Let's say i saw much more bluffs on a river on 5$ or 10$ limits as at 40c, 1$ for example. Same with double or third barrel without hit.