Ideas for Chocolate Stout bottling

Hi,

I have a chocolate stout in the fermentor at the moment and want to play around with some flavors when bottling.
So far I have thought of adding some mint essence to a couple of bottles and maybe some cinnamon to others.

Does anyone have any suggestions for what might taste great added to a chocolate stout and suggested quantities to add to bottles (350 ml)

Many Thanks

I myself have never added extra flavor to an individual bottle but rather to a whole batch. Easier I guess for my brain I guess. Coffee. Vanilla. Hard liquor.
all goes well with a stout depending on your taste. As for a specific amount per bottle if it was me I'd take the amount I'd put in for a 5 gal or 10 gallon batch of say bourbon soaked in vanilla bean. And divide it by the ounces in one bottle. I'm sure there are example on here if you do a search. Good luck. The mint sounds good.