This is a great question!
I think it depends on the situation and the people who I am responding to. Also, I've noticed that it depends on where I'm at in regards to my being honest/comfortable with myself in my decision to not drink.
In reading other people's replies to this question, I realized that lately when I'm offered a drink I reply "no thanks, I'm not drinking today." And that's 100% true! I'm taking this one day at a time, as they say.