I had no idea what was involved in planning a wedding before I planned one. Whenever I was invited to a wedding I tried to be polite and generally not bother the couple as much as possible. I think most people do this. I have tried not to be bridezilla, and I think I've done a fairly good job, but I just have to rant a little bit.
When you get a pre-addressed, pre-stamped rsvp card, please use it. I know that your life is complicated, and it takes time to figure things out, so I understand that you can't respond by the next day. However, there is a reason that there is a date you are supposed to respond by. It's because I have to tell the caterer how much food I need, and I have to pay for that food. If you haven't responded by the week before the wedding, respond that you are not coming. They are assuming you are not coming. Either don't do anything or respond with a no. This applies even as you are approaching 90. Yes, we can make room for one more, but please don't be offended that your name is not listed on the seating chart. It's because I did the seating chart more than three days before the wedding.
If you are invited to a rehearsal dinner. Respond. Most rehearsals are small and one person can make a big difference.
If you are strapped for cash, and need a place to stay, figure it out before the week of the wedding. If you don't, don't ask bridesmaids who are coming from out of town if you can stay with them. It puts them and inevitably, the bride, in an awkward situation. Also, if you read this and feel bad, don't call me and apologize. It's ok. I know, you didn't mean to offend, or anything, but you were busy and didn't get to it. I know. But I just had to get that off my chest.