This is going to be a short post. While some backpacking experience helps, one does not need to know any Philmont-specific skills or procedures before arrival. A Philmont Ranger accompanies every crew for the first few days of the hike and will teach these skills—even if the crew already knows them. A physically fit crew with light packs, good attitudes, and zero skills but a willingness to learn will be fine at Philmont.
So, don’t spend time practicing skills unless you are absolutely sure that (1) everyone in your crew is in tip-top shape, (2) you have good crew dynamics, and (3) every member of the crew has an appropriately light pack.
Even though you will be taught all the necessary skills at Philmont, I recommend at least one pre-Philmont shakedown hike to reinforce the need for packing appropriately. Everyone should carry full packs and at least 4 liters of water. The shakedown should be difficult enough to punish those with heavy packs and cause those with new boots to get blisters. Bring a scale to weigh the packs to reinforce the importance of packing light.
Again, don’t sweat the skills. You will learn skills at Philmont. You can’t learn fitness.
Vamonos Baby! 
While that may be solid advice for a traditional backpacking trek, I’d offer a different perspective for those preparing for a Cavalcade at Philmont.
In Cavalcade, fitness and efficiency with Philmont skills are both essential. There’s very little spare time, and the more practiced a crew is at setting up and breaking camp, packing panniers, and getting on the trail, the better their odds of arriving on time for program activities—or even getting tents up before a thunderstorm.
Cavalcade crews that move efficiently might enjoy a later wake-up time (say, 5:30 AM instead of 4:30). But slower crews often have to rise earlier to stay on schedule. So while skills will still be taught, coming in with solid working knowledge gives Cavalcade crews a huge advantage.
LikeLike