There’s a dumb title to a posting. Of course, you’ve got to get the serve in. What I’m talking about here is in your first service game.
Avoid the temptation to hit a big powerful serve to intimidate your opponent. The first game of the match is a time when you get the serve in and aim it at your opponent’s weaker side.
You absolutely don’t want the person to get a giant boost of confidence by watching you double fault the first game away to them.