It's been many years since I have drank, have been pregnant or BFing for the last 4 years, but I can try and help you out. with some more ideas. I do not like to drink liquor straight or on ice, I need something else with it.
The Amarula is best with milk and ice. Very yummy. It tastes like berries and cream.
The Amaretto is nice with Coke. It makes it taste like a Cherry Coke.
I do not like Kahlua or Grand Marnier but if you add some Baileys, you have a super yummy shooter. That is all 3 mixed together.
Enjoy!