When you fall off the track or get stuck somewhere, Lakitu comes to pull you out and place you on the track again.When he's about to drop you, press the acceleration at the exact moment you’re dropped onto the track and press on the Y or A button. Time it right and you’ll get a Turbo Boost for a short period of time.
Just before going off a ramp, press the R button to jump right when you are at the edge of the ramp for a turbo boost. If done correctly, your character will perform a trick in the air and you will receive a small burst of speed.
To get a turbo boost when the race starts, do not hold the acceleration button down before the countdown starts. Wait until just after the number 2 in the countdown disappears and then hold down the A or Y button. Do this to get a turbo boost as soon as the race begins and get a head start.
Toward the end of the Music Park Track there is a part where these Musical Notes bounce up and down every couple seconds. When these Musical Notes bounce they make the ground around them tremble and cause you to lose speed if you bounce. If you time it correctly and press the R Button right when you are bounced you will get a Turbo Boost for a short period of time.