One other interesting Chabad wedding minhag:
In other weddings, after the chupah, the couple is walked to the yichud room. The eidim check out the room, and leave and the couple goes in and locks everyone out.
By Lubavitch, the parents and others walk the couple to the yichud room. Someone puts a silver spoon down in the doorway, and the couple steps over it to go in. Then the parents enter and give the couple something to eat. (Whoever is in charge of the chossons 'Rebbe shirt' takes it off the chosson and takes it away.) There's so much mazal toving,that sometimes the mesader starts shooing people out so yichud can start.