First you will need to look into the change in elevation between your tee box and the green. While you could reach the green on just one shot you will need to choose the right club when you are going from the tee box based on the elevation difference between you and the cup. If the elevation of the green is lower than that of the elevation of the tee box you should look to go after the ball with a lighter club so that you will be able to keep from getting the ball to roll too far. You will also be able to take advantage of a lower amount of roll after you hit the ball.
You should not take the distance between you and the cup into consideration when you are going up to a par-3 hole. Be sure to consider the wind and elevation considerations of the hole when you choose a club. Sometimes a weaker or more powerful club might be a better option for you to use.
When you aim for the green you should aim you shot about ten feet beyond the green. This is easy to handle because most golfers tend to be more successful when putting from a shot past the hole than when it is short of the hole.
Another thing to do for your shot is to aim your shot in the right direction in the event that there is a tree or other obstacle located between you and the cup. You should aim twenty degrees away from the side of the obstruction in this case. You may not be able to get an easy shot at a birdie in this case but it will help you to at least look to get a good shot onto the green to possible try and get a shot at a par for the hole.
Be sure to use these tips for playing on a par-3 hole. By using these it will be easier for you to work towards getting a birdie or at least a par on a hole. Who knows, you just might even ace a hole when you use the right strategies.