2 Articles on Baji / Pigua Foundational Training Methods
from Journal of Asian Martial Arts
http://wutangcenter.com/wt/This is what I am most familiar with but other schools may do it differently
Everything started with baji horse stance & punching drills in place - then moving posture stances - then linkage to xiao baji form with breathing/posture execution - 3 basic da qiang exercises - hun yun qi gong - then to da bajiquan
Liu da kai & baji lian huan came much later
Again just based on my experience - we also had 2 person drills, drills with shields, two person da baji fight - some striking drills two person kao & one punch hitting partners shoulder.
One basic principle was called, I think, folding - not sure - once you commit it goes from fist, elbow shoulder/kao to head strike with head - baji the "bodyguard style" teaches how to generate power in short range application - striking is the centerpiece although xiao baji jia has short range SC usage - however this was my experiences 20 years past