Again, this will get easier to achieve once you have played for awhile and unlocked better boards. I did this on the Lv.1 Downhill Slalom with Sabre and the Grim Reaper board. Just get out in front as fast as you can, be careful to navigate through the gates so you don’t get a time penalty, and then don’t take any unnecessary chances.
Alternately, you can also do this easily on the Lv.1 "Fly Distance" event. All you are going to do in this event is jump straight up with your arms out at a "T". It is almost impossible to crash.