I was recently at a party where almost everyone was drinking. I made sure i always had a cup near me filled with a nonalcoholic drink. As soon as it was empty, i filled it again with the nonalcoholic drink so there was no time for it to sit empty. That way, if someone offered me a drink, i always had one already. I also found it easier to go right back to the nonalcoholic drink right away rather than sit with an empty cup for a while and think "hmmmm...maybe i could fill it with just half a glass of mojito since it's empty."