Here is a tip that might save you some time or headache...
Number those reply cards! Many a bride has a huge headache on her hands when, as sometimes happens, the occasional reply card is sent back with no names filled in. Clearly an oversight on the part of the guest who sent it, but how do you figure out who on earth it came from? Here's a little trick which will ensure that you avoid this problem all together - place a small, inconspicuous number on the back of each reply card before enclosing it with the invitation. Use a list to record each guest's name along with the number on the reply card you are enclosing for them. That way, if someone should forget to fill in their name, a quick glance at your list will tell you precisely who the reply belongs to.