Before jumping from a ramp press and hold 2 to go even higher.

Complete the event listed with either a gold, silver, or bronze medal.
Characters are listed in alphabetical order, then their outfits are listed by Tier.
Outfit --------------------- How to Unlock
Ammon's Tan Suit ----------- Saturday Matinee (Tier 9)
Ammon's Tommy T ------------ Seaside Village Race (Tier 6)
Ammon's Money Suit --------- Edinburgh Full Tricks (Tier 3)
Budd's Toys for Bob -------- Waterfront Race (Random)
Budd's Power of Chi -------- Rome Elimination (Tier 6)
Budd's The Bohemian -------- Catacombs Slalom (Tier 2)
Crash's Space Monkey ------- Lift Off (Tier 7)
Crash's Brace for Impact --- Out of the Woods Race (Tier 5)
Crash's Bombs Away --------- Fallen Empire Race (Tier 4)
Gunnar's Black Knight ------ Park It Anywhere (Tier 7)
Gunnar's Street Creds ------ Favela Rush (Tier 4)
Gunnar's High-G Armor ------ Gunnar's Threads (Tier 1)
Jynx's Graveyard Casual ---- Cable Car Tricks (Random)
Jynx's Funeral Fun --------- Del Centro Race (Tier 7)
Jynx's Black Tuesday ------- Road to Cuzco Race (Tier 3)
Kyla's Alpine Red ---------- San Francisco Full Slalom (Tier 9)
Kyla's Touchdown ----------- Clear the Streets (Tier 5)
Kyla's Shooting Star ------- Cuzco Challenge Race (Tier 2)
MacKenzie's Street Combat -------- Parking Lot Shuffle (Tier 7)
MacKenzie's Killer Bee ----- High Street Slalom (Tier 6)
MacKenzie's Spitfire Squadron ---- Edinburgh Full Race (Tier 4)
Tiffany's Military Chic ---- Shopping Spree (Tier 8)
Tiffany's Nero Style ------- Rome Burning (Tier 7)
Tiffany's Baby Blue ------- Tourist Spot Slalom (Tier 2)
Tony's Mariachi Loco ------- Out of the Woods Tricks (Random)
Tony's Business Camouflage - Mountain High Race (Random)
Tony's Downhill Jam -------- Hills Are Alive Race (Tier 9)

Complete the event listed with either a gold, silver, or bronze medal.

Skaters:
Unlockable ---------- How to Unlock
Kevin Stabb --------- Kevin's Challenge (Random)
Armando Gnutbagh ---- Unknown Skater (Tier 10)
Crash --------------- Crash Test (Tier 3)
MacKenzie ----------- MacKenzie's Challenge (Tier 2)

Boards:
Board --------------- How to Unlock
Chaos --------------- Vista Point Race (Random)
Dragon -------------- Swiss Elimination (Tier 9)
Goddess of Speed ---- The Hills Are Alive Tricks (Tier 9)
Makonga ------------- Mall Rats (Tier 8)
Black Icer ---------- Precision Shopping Slalom (Tier 7)
Dispersion ---------- Machu Picchu Top to Bottom Race (Tier 7)
Ripper -------------- Del Centro Slalom (Tier 7)
Spooky -------------- Clearance Sale (Tier 6)
Dark Sign ----------- He-Man Club/Girl Power (Tier 5)
Cruiser ------------- Grind Time (Tier 4)
Illuminate ---------- Machu Pichu Top to Bottom Tricks (Tier 4)
Red Rascal ---------- San Francisco Elimination (Tier 3)
Kuni ---------------- Hong Kong Race (Tier 2)
Street Issue -------- Street Issue Slalom (Tier 1)
Solar --------------- Tourist Trap (Tier 1)