I use some mouth watering flavor oils in my balm. but I don't sweeten, so there is no taste. they just smell delicious! My lips tend to be very dry, and when you have sweet stuff on your lips, you lick them more, which dries them out more....
I actually prefer unflavored entirely, but if you are going to put a flavor in it, please put in a sweetener or your flavor is just a fragrance cuz you can't taste it.