I would soak them all separately in very high concentration. Then use a dropper to make blends. Add those blends to some base beer (store-bought even) to see what you like and how much to use. I personally think rum would be better than tequila in Mexican hot chocolate.
Another idea is I have a book on bitters. Almost every recipe follows the same procedure. Soak in high-proof alcohol (overproof rum, whiskey, everclear, etc). Strain and then boil the spices in water. Cool, strain again and blend the water with alcohol. I suppose using cold, heat, water, and alcohol increases flavor extraction.
Side note- I've always been disappointed with soaking cinnamon sticks in beer. Seems difficult to get good flavor without heating.