At weddings the monogram often play a role in the decorations, maybe on the napkins or at the the smal rice bags. It's not a medieval faenomenon but you can easily make it so it stays within the theme.
This webpage has a lot of fonts for different writing programs, and with a little help from paint you can make a lot of beautifal monograms using the fonts under medieval.
These are my attempts with R and C:
We ended up chosing a much more simple design for ourselves:
Knock yourselves out :)