Methods to advance and retreat: connect the hands methods, draw in the opponent method, put the opponent under duress method, resist the opponent method, protect the body method.
Advance and retreat chuanzhang. One partner advances with chuanzhang while the other retreats, also doing chuanzhang. Both sides are actively involved, this does not train simply retreating from an attack. The retreating partner is training how to suck the attacker into your space, making him chase you. The retreating partner especially must remain calm and collected.