How do you remember the new words you look up when reading books? Making an Anki card for each will make sure those words are permanently etched into your memory.
I think that depends on your learning style, doesn’t it? In school they always want us to use the word in a sentence, and from my own experiences learning foreign languages and eastern philosophy, some words just don’t translate.
It’s a big reason why when you ask your friend what the two foreign characters in the movie are muttering they may pause and say, “this character is really mad at that character.” Because translating their swearing just does not make any sense in English, or sounds even harsher than it really is (according to screenplay writers, the French like to slip the word “whore” into any exclamation, from jovial mocking to impotent rage. Or perhaps more illustrative, there’s a “dang it” that refers to either a cow, or a dog’s name.)
Or going the other way, you want to explain “Bob’s your uncle” to a Swede? There’s a political history lesson in that explanation. They’re so weird you just learn them in context and go on, mostly.