Traditionally, ti qing done by the groom's family to the bride's as a request to marry the bride. They will present a letter officially with the initial gifts for the bride's family. This is done so with the help of mei po. They will then request for the birthdates of both bride and groom to select the auspicious date for marriage.
When both parties meet, they will discuss about the formal gifts required. This is what we called pin li, pin jin, hui li, jia zhang. All these gifts will be presented during Guo Da Li, which the groom's family will select an auspicious date to deliver the gifts.
I think the modern marriage is done just by having a meet-the-parents session officially.
Stacy, during GDL, your hubby will pack the agreed gifts (PJ, PL) in a multi-tiered wedding basket and present to your parents. Your parents will then present the HL and JZ.