You can make it for yourselves, or as a lovely gift to a newly wed!
Find a suitable picture on the internet, your search keywords could be something like “2d wedding gown/tux or cartoon wedding gown/tux” or so. Print it out and cut the pieces out.
Then, roll a thin sheet of black and white clay (or any colour you desire your outfit to be)
Place the cut out paper on top and use your x acto knife or blade to cut the base out.
Trim your picture so that the little details on top is a separated piece from its base (example : cuffs, tie, wedding dress ribbon, etc). Repeat the same thing as above : place the designs on top of your clay pieces and cut them out. Stick them on the base you created earlier on and you’re done!
Coat it with varnish and leave to dry. If you wish, you can also add the newly wed’s name on each keychain.
Simple and beautiful isn’t it?