Prior to pre-trip: Make great efforts to get everyone to the pre-trip. If someone absolutely can't make it, sit down with them, going through the information included below. Pre-trip meetings lessen liability, make trips run smoother, aid in preventing misunderstandings, and most importantly, make trips safer.
Overview of the Trip: What, When, Where. Discuss any special abilities or skills needed.
Common Adventurer Trip: If you are doing the trip as a common adventure which is great way for clubs and groups of friends to do trips, be sure discuss what it is: sharing of expenses & responsibilities. Trip initiators and helpers are not guides. Everyone's help is needed: help pack, help keep things safe, and help clean up after it's over.
Risks: Make everyone aware that the trip is not perfectly safe. List specific things that can go wrong. (It sounds stupid, but it's important). Everyone should make a careful choice whether they want to accept risks. No one should feel pressured into going. They should participate voluntarily. There's no problem if they decide not to attend. Make it easy for people to drop out.
Sign-up Sheets: If you have a school group, club or some other organization, have everyone re-sign a sign-up sheet at pre-trip meeting. Pass it around while you are talking about other items. Make sure they know that by signing they accept the risks, they are waiving their right to sue, and that they should have their own medical insurance.
Clothing & Equipment Needed for Trip: Make sure everyone is adequately prepared. Use equipment lists available on the Resources page.
Alcohol: At Idaho State University, it's easy. The University has a policy against alcohol use on trips. If, however, you are going on your own trip or it's a club trip, you'll want to talk about alcohol in advance. Establish some guidelines: is it OK during the day, and if so when is too much, too much? What about evenings? Having a plentiful supply in the evening could put some members of the group in an uncomfortable situation. People should enjoy themselves but they need to "be cool" about it as well. The best way of dealing with alcohol is to talk about the group's expectations before you leave. Don't forget to remind everyone that drinking and driving is not acceptable.
Minimal Impact: Discuss how everyone can minimize impact on the environment: fires vs. stove, human waste, littering, etc.
Health Concerns: It's important that you know about any special health problems that any members of the group may have. What you learn may determine what you take in a first aid kit. It may require that you take certain precautions while on the trip--and it may even require that plans for the trip be altered. Some medical problems may be inappropriate for the activity, and you may need to tactfully steer the individual away from the trip. To save embarrassment, announce at the pre-trip meeting that anyone with special medical problems (diabetes, bee or insect allergies, heart problems, etc.) should talk to you after the meeting. At that time you can meet with them on a one-to-one basis and decide on a course of action.
Transportation: Help get riders and drivers together. Arrange meeting times.
Organize Responsibilities: Put together groups. If you are doing group food, ask for volunteers to buy food. If needed, organize a few people to pick up any group gear (like rafts). Organize a clean-up group.
Trip Money: Appoint a treasurer. Collect a little more than expected. It's always easy to refund, but extremely hard to collect after the trip.