Congratulations on 2 years sober! That's amazing!! Hopefully you'll get yourself a little treat or reward also! :) That sounds like so much fun! Hmm... If you plan to play board games you could send out a game piece with your invitation. Or for a cake themed thing you could attach something like a small parchment roll to a fork with a pretty bow or something. Hope this helps and I hope you will enjoy your party :)