Summarize the following:
Before talking to your parents, you and your friends should get together and all figure out the details of the trip. The most important part of your trip  to figure out is where you are going to go. Even if you already know your destination, make sure you know exactly what region or area you want to visit. If you plan to visit multiple locations, make sure you know exactly where they are and how far apart they are from each other.  For instance, even if you know that you want to visit California, you can narrow down your trip to visiting San Francisco and San Jose. If you and your friends disagree on where to go, try to reach a consensus. If your parents pick up on the fact that you and your friends have different thoughts about the trip, they will be less likely to give their permission. Once you know where you're going, figure out how long your trip will take, including travel time. Make sure that you and your friends check a calendar and pick the exact dates you will be leaving and coming back. Check in with your friends about their schedules and coordinate a time that works best for everyone. Make a comprehensive day-by-day plan that details exactly where you will be throughout your trip. This is especially important if you are visiting multiple cities or countries. You need to know exactly what days you will be in each location. You also should figure out what main activity or activities you will be doing each day.  For example, one day in your schedule could be: “Monday, September 12: 3rd day in Mexico City. Visit the Anthropology Museum and the Casa Azul. Eat dinner downtown.” Hear your friends out and compromise when you are planning your activities. Once you know exactly where you'll be on each day of your trip, you can start to figure out how you will get from place to place. If you are travelling a long distance, you will have to fly to your destination. Then figure out how to get from place to place based on the plans that you laid out. Note the cost of the transportation.  Don't actually buy any tickets, just write down how much a ticket would cost. Figure out how where you will stay overnight for each part of the trip. Ask you friends if they know of anyone in the place you are visiting where you could stay. Also check out the prices of hotels and hostels, and write down several options. Aim to be economical, but don't stay somewhere that isn't reputable just because it's cheap. Add up the price of your transportation and lodgings. Then add the approximate amount you expect to spend per day on food and souvenirs. Add a little extra in case something comes up. This should give you a good estimate of the cost of the trip. Adding a little extra money to your budget in case of emergencies will help show your parents that you are responsible and thinking ahead. This may help convince them to let you go. Either type up or write down your itinerary. It should include everything that you have already worked on, and should be organized by day. Each day should include the main activities of the day along with the price of each hotel and method of transport. This will show your parents how much thought you put into your trip as well as give them an idea of the sorts of things you will be doing. This may help reassure them.

Summary:
Pinpoint where you want to go. Figure out how long your trip will be. Make a day by day plan. Figure out transportation. Find places to stay. Estimate the overall cost. Write out your itinerary.