Simply replace the unfilled areas such as "" and "[date]" with your information.
Dear [Affectionate Name],
Tomorrow night, you and I will be [on a plane/in a hotel] beginning our honeymoon. After a long chaotic day, I may not get to tell you how happy you have made me. So, I am writing to you now to tell you that I love you and I can't wait to marry you.
Can you believe our first night as husband and wife is only one day away? I know you are probably as nervous as I am, but it is going to be wonderful. Our life together is going to be spectacular. We have so many exciting and surprising things in store for us. There will be ups and downs, but through each adventure our love will only grow. I will be so proud to be your [husband/wife].
If I forget to tell you tomorrow, you look more [beautiful/handsome] than ever.
All my love,