If only Redlynx themselves knew how to teach FMX as such, more people might actually understand how it works :P . Good job Vantier!
An example of my best run so far: 2 million on surface tension 
Big thanks to Snikachu whom I figured out certain flip tricks from watching replays.
Also figured out a number of things about the FMX system, should be help people be a lot more consistent with it. Starting with...
Trick Flips
- Double and Triple trick flips actually count as their own separate trick (both front and back.) Meaning the correct formula for number of tricks in the game is actually: 13+(13*6)+1 = 92 Tricks
- Is this useful? In Surface Tension yes, as you can see from the above run I did. Probably not for other maps, however..
- Keep this in mind: the closer your rider is to the bike, the faster you will flip. For this reason, it is fastest to flip with the coffin, followed by going up, underdog, going to hell. And slowest to flip with kiss of death, dead body, polevault, and slash
- Making it preferable to do a double or even triple cofflin flip as opposed to a slash flip for instance, which can take a while to pull off.
- Might be easier for the less experienced to do these double flips as opposed to more complicated trick transitions.
Flip Transitions
Even if you are not interested in transitioning into another trick while flipping, this is relevant with regards to consistency.
- The trick your rider will perform is not only affected by the direction of your right stick, but by the momentum of your rider during the bike's rotation
- For instance, the most reliable way to do a front superman flip > driller is not by shifting the right stick down upon completing the flip, but by shifting it right, which triangulates the rider's clockwise momentum against the direction of the right stick, shifting him downwards into a driller.
- The most extreme case I can think of is the Front Going Up Flip -> Front Underdog Flip in my run^. The flip is so fast, you have to push hard left on the right stick as soon as the first trick locks to do a underdog, which is normally a right movement. A full 180 degrees, you can see how much flipping affects FMX.
- This effect happens even during small rotations, so bear that in mind the next your rider does something you don't want him to. Speaking of which...
Consistency
There are a number of little nuances with the trick system that make it appear inconsistent. I will attempt to list them here:
- Coffin and Proud hero will have trouble activating when your rider is leaning forward, due to where the legs are pointing initially.
- So for Proud Hero, a simple movement where you lean bike forward in air, then back to do Proud Hero is a nice fast movement.
- Coffin is easier to do within a flip or combo'd with Proud Hero than on its own, due to how leaning makes the trick easier to pull off. The rider can also scissor kick and flail around if you end the trick without appropriate leaning (best way to learn is through experience).
- You wanted to do a trick, but you did a coffin. Well this can happen for two reasons:
a.) There is a roughly half second delay between when you leave a ramp, and when FMX starts accepting input. For this reason, if you attempt to do for example a kiss of death or dead body right after leaving a ramp, it will miss most of your input and only see the final input, making it think you wanted to do a coffin. So to fix this, simply wait half a second from leaving the ramp before doing tricks.
b.) Transitioning from another trick, such as trying to go from going to heaven > kiss of death, and you mistimed it causing it do coffin. Do note that if this happens, it is a slightly different 'coffin'. Look closely, and you'll see the riders legs are above the handlebars. This means you can transition straight to kiss of death/slash/polevault/dead body by shifting the right stick into the same direction your riders legs are facing. Very useful for being consistent in Trick Master!
Landing tight trick sets/while holding a trick
- Do NOT accelerate when landing, keep off gas at all times, only apply when trick is locked and rider fully on bike.
- Let go of lean when ending trick, then reapply after letting go of RS. The aim is to revert the rider to the leaning position as fast as possible. If desperate attempt to spam left-right lean etc.
- Land as well as you can, bias towards landing on front tire on downhill slopes for instance, to maximise airtime.
- Luck will be a factor, but try and manipulate the odds in your favor 
Honestly though, even if you're struggling with the FMX system, platinums should be easy to get if you look up the replays and learn some simple transitions, where you don't return the right stick to the center, and just smoothly move it from one trick to the next, in order of difficulty: (RS = Right Stick)
- Superman > Ruler: straight bike, RS left then up.
- Superman > Going to Hell: straight bike, RS left, then rotate bike clockwise and RS up.
- Going Up > Going to Heaven: bike facing up: RS down then left.
- Going Up > Underdog: bike facing up, RS down, rotate bike anti-clockwise, RS right. Similar thing to do > Going to Hell (push RS more in the Up-Left direction to account for rider momentum)
- Coffin > Proud Hero: Keeping in mind the earlier consistency advice, hold the RS in the coffin direction your most comfortable with, then get the bike into a right-tilted position, lean back then RS down to do proud hero. Try doing this with a back coffln flip as well, and it should make more sense!
- Underdog > Bow: bike facing upside down: RS right, then rotating bike a little more anti-clockwise, keep RS right but move it up or down a tiny amount then hold it, should now do a bow.
- Slash > Kiss of Death: Wait a half a second leaving the ramp, then rotate your bike in the anti-clockwise direction and while pushing RS left, should separate the rider and the bike neatly into a slash, then rotate the bike up and RS up, smoothly into kiss of death.
- Also, you should minimize the amount of bike rotation with the left stick and make full use of the rider's momentum affecting the rotation with the right stick, allowing you to more seamlessly move from one trick to another with less movement.
Hope that helps some people