I have been baking for over 20 years, but lately have been getting back into the swing of it but baking cupcakes. I'm curious out of a basic cupcake recipe if I wanted to make 1 dozen assorted cupcakes how do I go about doing so, with add-ons, different flavors etc, without having to make different batters. Any input would be appreciated.

I make one vanilla cake batter that makes most of my flavors. Add lemon pudding/lemonade mix with lemon juice/zest/extract etc for lemon. Grand marnier orange zest and choc chips for grand marnier, etc, you get the picture. The possibilities are endless! I would just suggest taking your small amount of batter and adding everything to it at once so that' you're stirring as little as possible and not over-mixing the batter.