Letters

Within a Couples ceremony the partners exchange letters they have written to each other.  Prior to writing they are asked not to discuss the contents with each other.  The letters explain what they feel about each other and their hopes for the future.
The letters are sealed and exchanged during the ceremony.  (Often when making the promises.) 

The couple agree on a date in the future when they will sit together and open the letters. 

Letters can also be included in a Naming ceremony and be from any member of the family expressing their wishes and hopes for the child's future.