Tony Hawk's Pro Skater 2
Always try link things together. One ability I've found rather useful is the Casper to 360 Flip special. Go in with this and wait till it freestyles. Then jump right before the manual fails and go in to a grind (Darkslides and other special grinds work well for this). After the grind, jump out in to a heel/kickflip in to a manual, to another grind, to another heel/kickflip 180 to manual to heel/kickflip and land. If done right you will get around 35,000 points. Switch nets around 42,000. This is especially useful in Marseille and Skatestreet Ventura. Always try to link things on street with a manual. In vert use spins combined with a grab to a flip for monster points. Also, for quick flips in vert use R2 rather than left/right. Tap quickly 4-5 times and you will pull a 720/900.
Anohter good combo for tricks is in the Bullring: Line yourself up to go off of that offset portion of the halfpip that leads into the loop. Go up there, and ollie off to your right (get lots of air or this won't work). DO some spins, maybe a special, a grab and a fliptrick before doing your character's special grind on the rail at the top of the halfpipe. (and getting the Nailin' Da Rail trick). Grind all the way to the end, and leap off, doing spins and flips as you go. Land in a manual, steer over to the quarterpipe surrounding the bull track, and leap up onto the top to do another special grind. This'll net you about 80-175 000 points, which is good for competition (DUH!).
Just ride around on a level and look for combos and lines that you could do. One thing that I like to do is to set challenges for myself.Like try nollie-ing the Massive 20 set in Venice beach,Doing a 900 down the leap of faith,or doing only one grind without jump in the middle up the leap of faith, so it only says "5050 grind"...
Another thing that I would like to say is criticize the people that yell at THPS 2 for its lack of bluntslides...Well for someone that doesnt jump to conclusions, you would have realized that a Nosebluntslide is up,up,Y...and a bluntslide is down,down,Y.To tell the truth,these 2 grinds net you huge amounts of points for a single grind.It may take a while for you to get,but they are both good tricks.
Flying Skater - Pause, hold L1 and press up 4 times, ollie, flip, up 4 times, ollie, flip, up 4 times. To fly jump and hold ollie to fly up. Hold grind to hover.
Unlimited Special - Pause, hold L1 and press ollie, grind, grab, grab, up, left, grind, grab
All Stats at 10 - Pause, hold L1 and press ollie, grind, grab, flip, grind, up, down.
Fat Player - Pause, hold L1 and press ollie, ollie, ollie, ollie, left, ollie, ollie, ollie, ollie, left, ollie, ollie,ollie, ollie, left. Enter this code several times to make your guy even fatter!
Thin Player - Pause hold L1 and press x, x, x, x, square, x, x, x, x, square, x, x, x, x, square. You can do this several times too to increase the effect.
Blood Off - Pause, hold L1 and press right, up, square, triangle. Rpeat to turn it back on.
Big Head - Pause, hold L1 and press square, circle, left, left, square, right, up, left.
Super Ollie Height - Pause, hold L1 and press left, up, left, up, down, up, square, triangle, left, up, left, up, down, up, square triangle.
Unlock Almost Everything - This is the grand-daddy of codes. Pause, hold L1 and press x, x, x, square, triangle, up, down, left, up, square, triangle, x, triangle, circle, x, triangle, circle. Now choose "end run" after the screen shakes and a list will appear with what you have unlocked including Spiderman!