Your boost meter must be full and the red dot must be lit. The "tricky" music will play once this happens. You have 20 seconds to do an uber trick before the red dot goes out and the music stops. Make sure that the board you are riding is the same type as your character's default (Alpine, BX, etc.). Get some decent air and do any of your default grabs and tweak it. (I have the gamecube so that'd be L+B or R+B, etc.
After pulling off 6 ubers in one run, you'll fill up the letters T-R-I-C-K-Y and have full boost for the rest of the run.
The red dot does light up as mentioned above. On the PS2 version the red dot also spins around, and the speed of the rotation speeds up as the time to pull off the Uber Trick runs out.
At this point you have to do an Uber Trick which is not the same for every character. If you look in the manual (I can't believe I just recomended that!!!!) in the section on Uber tricks it says what you have to do for the characters. I dont have the book on me right now so I cant say exactly what page it's on, however its just in a small paragraph. The paragraph says that like 3 characters have to do one thing for an Uber trick, and all the rest do something different.
Just remember, I've only played the PS2 version so I can't say whether the stuff I said above pertains to any of the other versions.
What you are talking about is their "personalized" trick. In the Xbox version, there are something like 6 different Uber tricks for any given character, and they change depending on the type of board you are using, i. e. Alpine boards do different ubertricks for a given key combination than BX boards do.
also, on the PS2 version, when your TRICKY meter is full and that anoying music is playing, the trick that you need to do is at the bottom of the screen...normally i think you need to like hold R2 or L2 or something...a few secs before you hit the jump...and make sure you get some good air..because the TRICKY tricks are usually pretty detailed..and involve a lot of grabs and spins etc..you dont want to hit the ground in the middle of a UBER trick..
I believe it will only show the ubertricks while you are a newbie, or whatever that first level is. They disappear pretty quickly as you increase your character's level. At least on the Xbox, and I believe the PS2.
You are correct David. Also try to only do Ubers when you catch plenty of air. There are one or two Ubers per character that are short and can be done with minimal air but big air is better. (When you catch some really big air, try doing two Uber tricks in a row, that will net you some big points.) Come back and talk to me when you gotten a gold on Pipedreams in the showoff mode. Here's a hint, use the two halfpipes, not the bowls, to their full advantage. (And get as many orange and red snowflakes as you can.) Try to use up as much time on the clock as possible before moving on to the next section of the course. Mastering Ubertrick combos is a must on Pipedream. I got almost 900,000 on that course. It seems impossible, but it's not.