It's good to follow a rough timeline to make sure the outing details are known in advance, and you're not trying to cram the planning in at the last minute. Planning early allows the process to be more scout-led.
The Patrol Leader's Council decides on the overall trip big ideas. They can be as vague or as specific as they need. This is usually done at a Quarterly Planning Meeting. The plan should at least include a rough idea of what the PLC wants to do, and the dates for the trip. They also choose a Lead Scout for the trip. Soon after, the scoutmasters assign a Lead ASM and the outdoor coordinators assign an OC. It's good to have these decided between 6-9 months out. Since this far out it is not always possible to know whether you can go on a trip, scouts or Lead ASMs do not need to commit to attending.
This is the first phase that gets documented on a Outing Planning Sheet. The Lead Scout and Lead ASM work together to fill in details needed to make reservations or deposits. If the PLC already chose a campground, they figure out if it's available. If not, they find a campground that meets the PLC's desired activities. The Lead Scout finds out information about the campground like water and bathroom availability, parking, capacity, whether fires are permitted, etc. The Lead Scout and the Lead ASM ask the OC to make reservations, and they update the Troopmaster Calendar with any new details. The Lead Scout can also start filling in some information on the Information Sheet (last page of the outing planning sheet). If the trip needs any special equipment (like canoe rentals) or training (like a swimming test), the planning team starts to work that into the troop's schedule. This phase needs to be done 4-6 months in advance, or there is a risk that the campsite will already be reserved.
Continuing to work through the Outing Planning Sheet, the Lead ASM and Lead scout start to plan the campout. They find out what advancement or scouting activities are available, and come up with a rough schedule of events, including the time we depart for the trip, and the approximate time we will return. The Lead ASM figures out how much participants will have to pay, and whether any additional items are needed to register such as waiver forms or training. Once we know where we are going and what we will be doing, it's time to start allowing people to register. The planning team puts all relevant information into the Troopmaster event, and opens up registration. The Lead Scout can start making announcements about the upcoming trip. The Lead Scout reports the planning progress at the PLC, and the Lead ASM reports at the Scoutmaster's Meeting. The Lead Scout can fill in more of the information on the Information Sheet (last page of the outing planning sheet). This phase needs to be done about 2-3 months ahead of time. The due date for registering for the trip should be a full 2 weeks before the trip.
Once the trip registration is closed, the Lead Scout and the Lead ASM form the participants into patrols. They also figure out if the troop SPL or an ASPL is going so they can be the SPL for the trip, and if there is an elected patrol leader for each patrol. They try to respect the existing patrols as much as possible - if 3-4 scouts from the same patrol signed up for the trip, that can work as a patrol. This is when the Lead ASM decides whether the adults will cook and eat as an Adult Patrol, or the trip works better with the adults eating with a scout patrol. The Lead Scout delegates activity planning/leading responsibility to scouts or patrols, such as organizing a game, planning a cooking contest, hosting a campfire, or performing a flag retirement. This is also a good time for the Lead Scout and/or Lead ASM to hand off responsibility to a registered scout or ASM if they find out they cannot go on the trip. The Outdoor Coordinator makes sure participants have training (Swim Qualifications, Safeguarding Youth, Hazardous Weather, IOLS), medical forms, and payments. The Outdoor Coordinator also ensures enough drivers to transport participants and gear. This Phase normally has the scouts planning patrol duty rosters, grubmasters, quartermasters, menus during the 2nd Thursday before the trip, the grubmasters shopping for food during the 1st Thursday before the trip, and the quartermasters gathering the necessary patrol equipment during the 1st Thursday before the trip. The Lead Scout can complete and send out the Information Sheet. The Lead Scout continues to make announcements about the trip at closing flags.
The Lead Scout and Lead ASM help the SPL execute the planned activities. Each evening, the patrol leaders, Lead Scout, and SPL have a Patrol Leader's council so the patrols will know what is planned. This should be short. At the end of the trip, the scouts pack the cars and clean up the campsite, then a closing circle allows participants to share things that went poorly ("Thorns") and things that went well ("Roses"). We always do thorns before roses to end on a positive note. The Lead ASM usually shares the last rose, which can come in the form of a Scoutmaster Minute. At that point, the trip SPL decides whether the group is ready to leave to go home -- scouts should not leave before the closing circle. On the way home, the lead ASM or the Outdoor Coordinator email the entire troop with the ETA back at the church. Back at the church, the scouts put CLEAN patrol gear back in the correct storage locations, or they assign DIRTY gear to a patrol member to clean and return. No scout gets to leave until all gear is put away and the SPL dismisses the group. Extra food is put on the wall outside the shed for anyone to take home.
After the trip, the Lead Scout and Lead ASM make sure attendance is properly recorded, and scouts and adults are getting credit for camping nights, hiking miles, service hours, advancement sign-offs, etc. The Outdoor Coordinator should make sure all participants know how to get reimbursed for their expenses. At the next PLC, the Lead Scout reports how the trip went, and the Lead ASM reports at the Scoutmaster's Meeting. Any significant lessons learned are documented and stored on the shared drive. The Historian collects photos from participants and chooses some to go on the troop website.