When you can have a perfect lie, why give yourself a mediocre one? This is a question I ask on the frequent occasions when I see golfers, both good ones and bad, hitting a tee shot on a par-3 hole without teeing up the ball. These players simply drop the ball on the ground and roll it around with the club head until they get what they think is a satisfactory lie. But there is a chance that the lie is not satisfactory, and it certainly is not the best lie possible. On even the most closely mowed tees, blades of grass will come between the club face and the ball if the ball is not clear of the ground. The grass reduces the backspin that the club can put on the ball, and also accents the effect of any mistakes in the swing. The most frequent result is a shot that holds its line fairly well but "sails," ending up over the green. A par-3 hole can be hard enough, without making it tougher through carelessness. What you should do is tee the ball up so that it sits above the top of the grass. The club is then free to make clean, crisp contact with the ball.
When the ball is teed up (above) the club head can get at it cleanly and the club-face grooves can impart maximum backspin. But if the ball is simply put on the ground (below) grass can get between the club head and the ball and affect the shot.