Basically, this is what I have in mind:
- Step 1: Buy a book in your target language (the language you want to learn).
- Step 2: Buy the same book in your source language (likely your native language).
- Step 3: Translate paragraphs of the source-language book into the target language.
- Step 4: Compare your translation with the target-language translation: what's good and what's bad?
The underlying idea is that you're comparing your translation of a text with a professional translation, and hopefully identifying ways to improve your writing (particularly grammar and word choice).
Question: Is this technique used to improve writing skills?
I've never heard of this before, but I'd guess I'm not the first person to think of this; perhaps it has a technical name.