Stevia is so gross. It ruins anything it touches. Aspartame is ok. Splenda is a migraine trigger.

For coffee, a demitasse spoon of sugar - moderation is the way, or I like a lot of milk no sugar (but that probably ends up with the same amount of sugar from lactose)

For tea, mostly unsweet is fine.

For soda, moderation again but I like the diet version better than the sugared ones. Diet coke is fine and doesn't give me a headache. Once in a while though, not every day. Just when I want something that is nothing.