This isnt as hard as you might think, the tricky part is keeping your balance over 90.
Wind - dont look at flags or your coach etc (like it says in the tutorial) watch the wind gauge bottom right of screen, wait for it to go one way the as it starts to drop towards 0 again try to hit A as close to 0 as possible.
Push Off - You only have around 5 sec to get this so dont waste time and try to hit A when the power bar is full.
Launch - You want to start your launch just as your reaching the bottom of the slope, right before it curves and begins to slope upwards.
Balance - Ok the tricky bit, as soon as the launch has locked and you leave the end of the ramp start button mashing LT and RT as quick as you can this should keep your balance above 90.
Landing - Once the landing metre comes up you want to try to hit A just before it reaches the bottom, dont leave it to long otherwise you risk faceplanting the snow.
I tried a few techniques for balance and this definately worked best when i finaly got the ach i hit:
Wind - 98
Push off - 100
Launch - 96
Balance - 97
Landing - 94
Hope this helps!!