Mmmmm. . .yum. I add granulated sugar at the beginning to give it a chance to dissolve, then whip it good until it holds a soft shape, and then turn the speed down to medium and add flavoring a teaspoon at a time until I like the taste.

Get your whipped cream almost done, then add your liquid flavoring. I routinely do this with brandy and Kaluha. The cream should already be fairly thick when you add your liquid.

I would whip the cream about half way, just as it begins to thicken but before you are at soft peaks, and then add flavorings like schanpps or vanilla.