We always just give what feels right. That is a combination of how much we like the couple, how close we are to them, and whether there is any precedent (usually in the case of family weddings). The latter is only important because people in close circles do talk and we don't want one relative thinking we care less about them than another. It's unnecessary drama if nothing else.I've never liked the "cover your plate" rule. A gift is a gift, not payment.