To really answer that question would take writing a book. My methodology, and i don’t want to speak for Mark too much but I think it’s safe to say his too, is based on things like training heavy, focusing on breaking personal records, sticking with the basics, training movements and not muscles, and really concentrating on the squat and squatting often.
I’m sure you’ve heard all that before, I suppose sometimes the devil is in the details. A few that i think are important are… Most of the athletes i train squat 3 times a week. Most focus heavily on multiple sets of 5 in the squat. We pull from the floor hard and often, doing some form of pulling (cleans, snatches, deadlifts, clean or snatch pulls, romanian deadlifts) almost every training day, usually 3-5 days a week. My guys know how to clean correctly, and use big numbers on the clean and snatch, with many of them cleaning above 80% of their best back squats. We train when tired, we train when sore.
We maintain a competitive atmosphere in the weightroom. Record boards with all-time best lifts, another board wiped clean every monday morning which lists as the week goes by the “good” performances that week, athletes of the same peformance levels training together and trying to drive each other into the ground, these are all part of the motivation to kick butt and improve every time you step into the weight room.
I don’t think there are any gimmicks that work, and i don’t think there are any secrets other than learning to do lifts correctly and working very, very hard.
I know I didnt post much about specifics of manipulating volume or intensity. Within the basic framework given above, there are so many different things we do, and it would be really hard, even dishonest, to sit down and say “this is what we do” because it is always changing, adapting, and hopefully improving.