To create a detailed itinerary, start by organizing your trip day by day—listing destinations, activities, travel times, accommodations, and meal options. Use tools like Pinerary, where you can view or create an itinerary with real traveler insights to make your planning more accurate and personalized. A well-structured itinerary helps avoid last-minute confusion and ensures you make the most of your trip. Include time estimates, confirmation numbers, and backup options to stay flexible yet prepared.