First off it is worth saying that you can absolutely drink Kahlúa straight. It is such a delicious drink on its own that there is no reason why you can’t enjoy this as a shot or on the rocks as and when the occasion arises.
The wonderful thing about it is that it is as tasty on its own as it is in hot drinks, cold deserts, and both long and short cocktails.
There is no “should” with Kahlúa, so let your imagination run wild and use it when you’re dreaming up a new dessert or when you want to hunker down under the blankets with a slightly spiked hot chocolate.