Watch carefully when the race begins. Just after the word "Go" disapears, press UP twice. If done correctly you should get a jump start and be ahead of the other racers.
Finish first overall in the various difficulty stages of the Competition Mode to earn the hidden boarders Ben, Nieno, Tok, and Boreth.
Press B, R, or Z after jumping and hold the stick in any direction. Hold one button at a time to complete different grabs.
To earn the following hidden boards, finish first on all races: XXX6, Top Gear Rally, and Midway.
To earn the Bucky Board, complete the Stunt Challenge Mode.
To earn the Flower Board, place first in all 3 of the courses in the first round of competition mode.
More Bonus Boards and Mirror Tracks
You must have all levels open completely, and the best record on each track on each difficulty has to be beaten. (ex. you must beat the track records on say, polar paradise, on easy, medium, and hard). A ghost should appear on the hard setting on the track.
Beat the ghost and earn a bonus board. Then, play with that board against on the same track again. (ex. you will earn the 'Jake' board when you beat the ghost on polar paradise, so use the jake board against him)if you beat the ghost, you will earn the mirror of the the track! These are the boards you must use on the certain tracks:
Twisty -- Twisty Canyon
Jake -- Polar Paradise
'55 -- Splash Down
Tareh -- Glacier Gluch
Typhoon -- Easy Slider
Lynwood -- Funky Town
Back Flip -- Up, Down, A (you can do a lot of these by holding down after you hit A.)
Egg Flip -- Left, Right, A
Front Flip -- Down, Up, A (you can only complete one of these in a jump)
McTwist 720 -- Right, Down, Left, Up, A
Misty Flip -- Right, Down, Left, A
Rodeo Flip -- Up-Left, Down-Right, A
Spin -- Hold left or right on the d-pad and tap A to complete a spin. The longer you hold right or left, the longer you spin.
Easy Slider -- Easy->hard difficulty levels
Right after the first pinwheel, turn a sharp left and find a shortcut and a jump
Keep going until you get to the train overpass. Jump the bump behind the truck that is off to the left for another shortcut and jump
Twisty Canyon -- Easy->normal difficulty levels
Go to the right whenever there is a fork in the road
After the 2nd fork in the road, go until the roads merge. You will get to a big jump. At the bottom of it there is a blue fence. Jump it.
Polar Paradise -- easy->normal
Go until you see a little bump coming out from the right side (it has two little jump arrows on it). Just at the bottom, to the right are a set of arrows telling you to go left. Go right up next to the arrows. There is a jump right after (no little jump signs though). you will see two trees at the bottom. Go between them. After a few seconds you will see a tree that you can grind. Grind it. You will land back on the path.
Keep going until you see a jump surrounded by an arched rock. Use it. Follow the left wall until you see 2 trees. Go between them and jump the fence. Go slightly right and you will land on a rock (this takes lots of practice). At the bottom you with land on the normal path.
Funky Town -- normal->hard difficulty levels
Go until you get to the bridge. DON'T jump the hole, go down through it. Follow the mining tunnels and you are home free.