‘Poetry is what gets lost in translation’, -American poet Robert Frost. Every translation is an interpretative act, as well as a creative one. Translators read the original piece and try to work out what it’s doing, what’s important that’s going on. They are constantly making choices about which elements of a text to preserve and foreground, and which to sacrifice.
It requires very close and careful and thoughtful reading.and careful and thoughtful writing. Focusing on the detail makes you aware of this better than anything. If the writer has used word x, we need to know why that was the word he chose of all the options (what exactly does it mean, but also what’s it doing in the sentence, in the rhythm of the sentence and to the sound and register), and then we need to find a way of replicating that in English, again with the greatest precision possible.