The best approach for an upper B1 learner is to read each chapter first for overall understanding, then go back and look up only the words that are essential to the plot or reappear frequently. This balances comprehension with flow, avoiding the overwhelm of translating everything upfront or the frustration of missing too much context.
Here's why that works. At B1, you can understand enough to get the gist, and reading without stopping builds your natural sense of the language. If you translate every advanced word before or during reading, you'll break the rhythm and lose motivation. If you highlight everything, you'll end up with a book full of marks and no clear priorities. The key is to be selective.
Practical steps: Start by reading one chapter straight through, underlining or noting only words that block your understanding of a key event or character motivation. After finishing the chapter, look up those words (use a monolingual dictionary if possible, or a bilingual one for very rare terms). Write them down in a small notebook or app, but limit yourself to 5-10 per chapter. Then read the chapter again, now with the new words fresh. This repetition reinforces learning without overloading you.
For advanced vocabulary that isn't critical, let it go. You'll pick it up through repeated exposure in later chapters. If you find yourself stopping every sentence, the book might be too hard. Consider switching to graded readers or shorter texts at your level, then return to this book later.
What about pre-reading vocabulary? It's not efficient. You'd spend hours on words that may not appear often, and you'd lose the natural discovery that makes reading rewarding. Instead, focus on words that matter to the story. Over time, your active vocabulary will grow, and you'll need fewer look-ups.
Honest tradeoffs: This method works well for narrative books (novels, stories) but less for dense non-fiction or poetry. For those, you may need to read smaller sections and look up more words. Also, if your goal is to learn specific academic or technical vocabulary, a different approach (like spaced repetition with pre-selected word lists) might be better.
Next steps: Pick a book you genuinely enjoy. Start with a chapter using the method above. After 3-4 chapters, assess if you're understanding enough to continue. If not, try a simpler book. Consistency beats intensity: 15-20 minutes daily is more effective than a long session once a week.