Hold the remote pointing down toward the floor, like an actual golf club. Adjust your positon by using the left and right direction pad. The line on the map and the power bar are meant to be used together. Do a few practice shots to make sure you don't go into the red or go to far.
Step2
When you are ready to hit press the A button and hold all the way through. When you swing make sure that you and your Mii are lined up, otherwise you might go back and the Mii will swing and hit the ball.
Step3
When you finally get on the green you can push the 1 and 2 buttons to see all the bumps and hills. Wind has no effect here.
Tips & Warnings
Adjust for wind, I've gotten up to 30 mph. Try to go in the opposite direction of the wind. If it is going against you hit a tad bit harder. If its going with you don't hit as hard.
The up and down directon pad changes the club.
Sometimes it might be a good thing to go into the red on the power bar but becareful when you use.