The first opportunity to get this trophy is on Level 25. Starting then, you'll see green arrows appearing. Simply hitting one of these, even if you aren't boosting, will be enough to earn you this trophy.
Keep in mind that there is also a trophy for hitting all of the speed pads on level 25. Take your time getting through the mission, and you should be able to hit them all on your first try, netting you two trophies.