Trying to remember what you're doing each time is hard. I'm pulling and posting this from x360a as it's what will make it easiest for you to complete it.
Please make sure you finish each race as sometimes this achievement seems to pop when you land, mine popped before I even hit the ground or it won't pop until you actually finish the race. So play safe and finish the race if you think you got them all and it didn't pop.
Here's the link: http://www.xbox360achievements.org/forum/showthread.php?t=93...
and here is a copy and paste of what CrustyDirtDemon posted at the link:
Ok lets start out by saying that it was annoying doing every trick and then writing it down, but I figure this will be helpful for any one who wants to print or copy and past and then after doing a trick checking it off, also the best place to obtain this achievement was on 'Ghost Creek" using a class A bike, and during a Race event in world tour. Also I used the rider who is from Japan...If anyone has questions feel free to contact me on Xbox Live, GT: CrustyDirtDemon
A button tricks:
Up: Bar Hop Up Modified: Shaolin
Left: Nac Nac Left Modified: One handed nac nac
Right: Nac Nac Right Modified: One Handed nac nac
Down: Coffin Down Modified: Lazy Boy
Up/Left: Can Can Up/Left Modified: 2 footed can can
Up/Right: Can Can Up/Right Modified: 2 footed can can
Down/Left: Look Over Down/Left Modified: Point Break
Down/Right: Look Over Down/Right Modified: Point Break
B button tricks:
Up: Cordova Up Modified: One footed cordova
Left: Running Man Left Modified: 90 O'Clock
Right: Running Man Right Modified: 90 O'Clock
Down: Superman Down Modified: Superman Seat Grab
Up/Left: Supercan Up/Left Modified: Supercan Indy
Up/Right: Supercan Up/Right Modified: Supercan Indy
Down/Left: Indian Air Down/Left Modified: One footed Indian Air
Down/Right: Indian Air Down/Right Modified: One footed Indian Air
Y button Tricks:
Up: Ruler Up Modified: Scorpion Fender Kiss
Left: Madcopter Left Modified: Flinstone
Right: Madcopter Right Modified: Flinstone
Down: Clifhanger Down Modified: Sky Scraper
Up/Left: Side Show Up/Left Modified: Tweak Air
Up/Right: Side Show Up/Right Modified: Tweak Air
Down/Left: Superman Seatgrab Down/Left Modified: Indy Superman Seatgrab
Down/Right: Superman Seatgrab Down/Right Modified: Indy Superman Seatgrab
It may seem odd that you’re doing the same tricks twice with certain button combinations, but the game considers them different since the rider performs the trick on the opposite side of the bike...
I don’t mind if this is reproduced for any reason as long as credit is given where deserved...
last tid bit from me. I used my laptop with MS word. copy and pasted all the tricks. Made sure I did one by one and read the name at the bottom of the screen to make sure both trick names showed up for what I was trying to do. Once I landed safely, I marked them in red and went down the link until it was all red and I didn't miss any name.