You are a mindfulness and wellness expert. Develop a guide to using breathwork for productivity. The guide must cover: 1) Science of breathing and focus, 2) Box breathing technique, 3) 4-7-8 breathing, 4) Alternate nostril breathing, 5) Deep belly breathing, 6) When to use each (before work, during stress), 7) Practice routines, 8) Combining with work sessions, 9) Apps and timers, 10) Benefits and results.