This is a very useful move for preventing your kart from loosing speed around corners.
While moving around a corner, press the "R" button and move the control stick toward the inside of the turn. You'll notice "VVVVEEEEEEEEE" start to form out of your smoke trail.
This move will allow your kart to get a small boost after a turn.
To do this, you must first know how to do a Power Slide (shown above). On a turn, use the Power Silde, but while doing it, move the control stick to the instide of the track and then to the outside and back again really fast. You'll notice that the Es have changed from white to yellow. Repeat this again and the Es will turn to orange. Once they turn orange you can move out of the Power Slide and you will notice that you've gotten a Mini-Turbo.
With this move, you'll be able to turn around in one spot.
Press and hold "B" and "A" at the same time while pushing the
control stick to either the left or the right.
It's obvious what this move does... Press back on the control stick and "B".
If you whan to get rid of those slow starts at the beggining of a race, simply press "A" once the light turns green.
By using a turbo mushroom while aiming directly at another kart, you
can do a super high jump if you do this:
Charge at another kart with your mushroom. Once you and the other kart are just about to collide, use "R" to jump. You'll just fly over their head and anything else that happens to be around you. This move is very useful if you are in last place at the starting line (you'll have to get a turbo start), or in Battle Mode when a heavy weight come charging at you.
When you hit a bannana, imeadiatly press the break (B) then step on the gass (A) as fast as possible to avoid spinning out. This is really handy in the Battle mode because you won't loose a balloon!
If you're tailing right behined someone and need some way to boost your karts speed just a little, move up directly behined the kart in front of you so that you're almost touching. You'll notice that your kart will increase speed and air will come out both sides of your kart. It gives you just enough speed to pass whomever is in front of you.