First, plan early. For a trip in July, we generally have our first informational meeting in January. In February deposits are due, and by March the team is solidified.
Have accurate information to give to parents. This includes travel dates, cost, contact information, packing list, etc. The more you can give parents, the better. You can't over-communicate.
Help the students understand what they might experience. We can't plan for everything, but we can help them prepare spiritually, emotionally, and sometimes culturally.
The week before you leave get the students to have all their prescriptions filled, get spending money, clothes washed and even pack a couple days early. We traditionally have a prayer and dessert night a couple days before leaving. This is open to all family and friends to come and connect with one another, make sure parents have contact information and itinerary, and to remind them one last time on when to meet the day of departure.
There is a lot more to cover, so I will post them as I have time on our mission trip. We leave this Friday!