Vanilla beans were split and chopped up, then soaked in 100ml of dark rum for 2 weeks. The rum was then strained and added to the mix at bottling.
'Plain' - i.e. add nothing at bottling
Coffee - 100ml of strong coffee/espresso
Ginger - 100ml rum with 2 inches fresh ginger root chopped up finely, soaked for 2 weeks.
You can of course use any other addition here!