This is just a fun thing I wish I had done.

Write love letters to your fiancé that he'll read the day of your wedding. You may not have a lot of time alone that day, but the written word is a pretty powerful substitute. And if you write letters to each other, you're guaranteed to remember at least something from that crazy day, because you can save those letters.

And what if you would like to do personal vows but know you'd be too nervous to say them in front of people? A letter is a good substitute for that, too.