So some folks wanted to know how the scoring system works so I began working on that as a break from the leaderboard struggle. This is still a work in progress.
First of all the base score (I say base score, but there are times when it seems closer to a rounded off perfect score) of a given trick is always given in the right hand corner of tiny popout that accompanies each trick you perform. This also doubles as your estimated total combo score.
A trick's base score is affected by your landing, stance, spin, and the amount of air you get (speed does not seem to be a factor - you should use this to your advantage). Even within a Perfect landing there is still room for your score to slightly fluctuate based upon just how perfectly you land (similar to how some rhythm games have a percentage perfect mechanic)
Furthermore the more times you do a trick the more its base score decreases in increments until it hits a hard limit (this seems to be 75% of the base score). So for example a perfect ollie nets you ~189 points, the next ollie nets you ~185, one more ~181, all the way until ~144. It doesn't matter whether you do the same trick in succession or varied throughout your combo (even sloppy versions) as it is counted level-wide.
Now lets move on to the tricks. Wherever possible I have performed these tricks on level flatland.
Ollie/Heelflip/Kickflip (Notes: Ollie is naturally very quick and you can spin more than you otherwise could in a heel or kickflip)
Base score: 100+
Sketchy: ~71
Ok: ~94
Sick: ~142
Perfect: ~189
Frontside/Backside Shove-It
Base score: 300+
Ok: ~189
Sick: ~284
Perfect: ~378
Inward/Varial Heelflip/Hardflip/Shove-It Flip (Note: You'll notice that these tricks are performed in the same manner as the front and backside shove-it, albeit horizontally, and yet net you about double the points)
Base score: 700+
Ok: ~378
Sick: ~568
Perfect: ~757
Frontside/Backside 360 Shove-It/Laserflip/ 360 Flip (Note: I actually couldn't get the timing to land it just ok...)
Base score: 1000+
Sick: ~852
Perfect: ~1136
Dolphin Flip/ Anti-Casper Flip/Impossible
Base score: 1000+
Sick: ~994
Perfect: ~1325
Frontside/Backside 540 Shove-It (Note: I found that at this point on level flatland you're either going to get a sloppy or perfect landing)
Base score: 1000+
Perfect: ~1704
360 Inward Heelflip/360 Hardflip
Base score: 1000+
Perfect: ~1514
Inward Heel Late FS Shove-It/Hardflip Late BS Shove-It (Note: Almost exclusively never ever use these tricks because the motion is so inflexible and the animation is too long - you probably won't be able to get a spin in, severely detracting from its usefulness)
Base score: 1000+
Perfect: ~1893
Frontside/Backside Flip (Note: Technically Frontside/Backside Flip 180s as having the triggers held automatically begins the spin. This is the same for most trigger dependent tricks)
Base score: 1000+
Sick: ~929
Perfect: ~1239
Frontside/Backside Heelflip (Note: If you land this perfectly perfect you will get 2000 points. I've listed 1975 because that is what I get when playing casually)
Base score: 1000+
Ok: ~991
Sick: ~1500
Perfect: ~1975
Frontside/Backside Bigspin
Base score: 2000+
Ok: ~1382
Sick: ~2074
Perfect: ~2777
Bigspin Heel/Bigspin Flip
Base score: 3000+
Sick: ~2351
Perfect: ~3147
Double Heelflip/Kickflip/Shove-It Late Flip/Kickflip Underflip (Note: At this point these tricks really shouldn't or can't be performed on flatland. You will need some air or a bit of a drop to use them effectively. Everyone should endeavour to at least learn these tricks as their motions aren't too far removed from the basic tricks)
Base score: 6000+
Ok: ~3395
Sick: ~5093
Perfect: ~6791
Double Laserflip/720 Flip (Note: I actually think the 720 flip motion can be learnt fairly naturally compared to the double laser. I don't know if that is simply due to the placement of the analog stick lending itself that status)
Base score: 7000+
Sick: ~5433
Perfect: ~7244
That's enough for now. I haven't even gone into all the other tricks, stances and spins in detail yet.